Four hundred is the natural number following three hundred ninety-nine and preceding four hundred one. Natural number can mean either a positive integer (1, 2, 3, 4, ...) or a non-negative integer (0, 1, 2, 3, 4, ...). Natural numbers have two main purposes: they can be used for counting (there are 3 apples on the table), or they can be used for ordering (this is...

In linguistics, cardinal numbers is the name given to number words that are used for quantity (one, two, three), as opposed to ordinal numbers, words that are used for order (first, second, third). ... Commonly, ordinal numbers, or ordinals for short, are numbers used to denote the position in an ordered sequence: first, second, third, fourth, etc. ... In mathematics, factorization or factoring is the decomposition of an object (for example, a number, a polynomial, or a matrix) into a product of other objects, or factors, which when multiplied together give the original. ... The system of Roman numerals is a numeral system originating in ancient Rome, and was adapted from Etruscan numerals. ... Jump to: navigation, search The binary numeral system represents numeric values using two symbols, typically 0 and 1. ... A duodecimal multiplication table The duodecimal (also known as base-twelve or dozenal) system is a numeral system using twelve as its base. ... In mathematics and computer science, hexadecimal, or simply hex, is a numeral system with a radix or base of 16 usually written using the symbols 0–9 and A–F or a–f. ... The vigesimal (base-twenty) is a numeral system which is based on twenty. ... Jump to: navigation, search Hebrew is a Semitic language of the Afro-Asiatic language family spoken by 6 million people mainly in Israel, parts of the Palestinian territories, the United States and by Jewish communities around the world. ...

Mathematical properties

400 is the square of 20. In mathematics, a square number, sometimes also called a perfect square, is an integer that can be written as the square of some other integer. ... 20 (twenty) is the natural number following 19 and preceding 21. ...

A circle is divided into 400 gradians, which is equal to 360 degrees and 2π radians. (Degrees and radians are the preferred units). In Euclidean geometry, a circle is the set of all points in a plane at a fixed distance, called the radius, from a fixed point, called the centre. ... The gon is a measurement of plane angles, corresponding to 1/400 of a full circle, thus dividing a right angle in 100. ... A degree (in full, a degree of arc), usually symbolized °, is a measurement of plane angle, representing 1／360 of a full rotation. ... See Radian (band) for the Austrian trio. ...

400 is a self number in base 10, since there is no integer that added to the sum of its own digits results in 400. On the other hand, 400 is divisible by the sum of its own base 10 digits, making it a Harshad number. A self number or Colombian number is an integer which, in a given base, can not be generated by any other integer added to the sum of its digits. ... A Harshad number, or Niven number, is an integer that is divisible by the sum of its digits in a given number base. ...

Other fields

Four hundred is also

• a common ISO-standard film speed for photographic films.
• an HTTP status code for a bad request.
• a phrase meaning the wealthiest, most famous, or most powerful social group, leading to the generation of such lists as the Forbes 400
• in the title of the film Les Quatre Cent Coups (The 400 Blows), a French film directed by François Truffaut.

For the year 400 AD, see 400. Logo of the International Organization for Standardization The International Organization for Standardization (ISO or iso) is an international standard-setting body composed of representatives from national standards bodies. ... Film speed is the measure of a photographic film stocks sensitivity to light. ... HTTP (for HyperText Transfer Protocol) is the primary method used to convey information on the World Wide Web. ... The Forbes 400 is an annual list published by Forbes magazine of the wealthiest 400 people in the United States. ... Jump to: navigation, search Les Quatre Cent Coups (The 400 Blows) (1959) is a French film directed by François Truffaut. ... François Truffaut François Roland Truffaut (born in Paris, on February 6, 1932; died in Neuilly-sur-Seine on October 21, 1984) was one of the founders of the French New Wave in filmmaking, and remains an icon of the French film industry. ... Events First invasion of Italy by Alaric (probable date). ...

See also: three hundred, five hundred Three hundred is the natural number following two hundred ninety-nine and preceding three hundred one. ... Five hundred is the natural number following four hundred ninety-nine and preceding five hundred one. ...

401 prime number, tetranacci number, sum of seven consecutive primes (43 + 47 + 53 + 59 + 61 + 67 + 71), sum of nine consecutive primes (29 + 31 + 37 + 41 + 43 + 47 + 53 + 59 + 61), Chen prime, Eisenstein prime with no imaginary part, Mertens function returns 0. Also, area code for Rhode Island, also HTTP status code for an unauthorized request, also in the name of a retirement plan, 401(k) Jump to: navigation, search In mathematics, a prime number (or prime) is a natural number greater than one whose only positive divisors are one and itself. ... In mathematics, the Fibonacci numbers form a sequence defined recursively by: In words: you start with 0 and 1, and then produce the next Fibonacci number by adding the two previous Fibonacci numbers. ... A prime number p is called a Chen prime if p + 2 is either a prime or a semiprime. ... An Eisenstein prime is an Eisenstein integer aω + b that has only two Eisenstein divisors, the complex cube root of unity and aω + b itself. ... In number theory, the Mertens function is where μ(k) is the Möbius function. ... A telephone numbering plan is a system that allows subscribers to make and receive telephone calls across long distances. ... State nickname: The Ocean State, Little Rhody Other U.S. States Capital Providence Largest city Providence Governor Donald Carcieri (R) Senators Jack Reed (D) Lincoln Chafee (R) Official languages None Area 4,005 km² (50th)  - Land 2,709 km²  - Water 1,296 km² (32. ...

402 = 2 × 3 × 67, sphenic number, nontotient, Harshad number, also HTTP status code for payment required A sphenic number is a positive integer that is the product of three distinct prime factors. ... A nontotient is a positive integer n which is not in the range of Eulers totient function φ, that is, for which φ(x) = n has no solution. ...

403 = 13 × 31, Mertens function returns 0. Also, HTTP status code for forbidden, also in the name of a retirement plan, 403(b)

404 = 2² × 101, Mertens function returns 0, nontotient, noncototient. Also, HTTP status code for "file not found", perhaps the most famous HTTP status code of all time. A noncototient is a positive integer n that can not be expressed as the difference between a positive integer m and the number of coprime integers below it. ... Netscape Navigator displaying the 404 error page at eBay The 404 or Not Found error message, as commonly encountered when using a web browser on the World Wide Web, is a manifestation of one of the standard response codes of the Webs principal communication protocol, HTTP. When communicating via...

405 = 3⁴ × 5, Mertens function returns 0, Harshad number, HTTP error code for "Method not allowed"

Wikisource has original text related to this article:

406

406 = 2 × 7 × 29, sphenic number, triangular number, centered nonagonal number, nontotient, untouchable number, also area code for Montana, and HTTP error code for "Not acceptable". Wikipedia does not have an article with this exact name. ... Wikisource, The Free Library, is a Wikimedia project to build a free wiki library of primary source texts, along with translations of source-texts into any language and other supporting materials. ... A triangular number is a number that can be arranged in the shape of an equilateral triangle. ... A centered nonagonal number is a centered figurate number that represents a nonagon with a dot in the center and all other dots surrounding the center dot in successive nonagonal layers. ... An untouchable number is an integer that can not be expressed as the sum of the proper divisors of any integer. ... The western one-third of the state is primarily mountainous terrain, while the eastern two-third is part of the northern Great Plains. ...

"406" is a poem by John Boyle O'Reilly. It was believed to have been the number of one of O'Reilly's prison cells, and was the number of his first hotel room after he arrived in the United States. Hence the number had a mystical significance to him, as intimated in the poem. John Boyle OReilly (28 June 1844–10 August 1890) was an Irish-born poet and novelist. ... Mysticism, from the Greek (mueo, to conceal), is the pursuit of achieving communion with, or conscious awareness of ultimate reality, the divine, spiritual truth, or God through direct, personal experience (intuition or insight) rather than rational thought; the belief in the existence of realities beyond perceptual or intellectual apprehension that...

407 = 11 × 37,

• sum of three consecutive primes (131 + 137 + 139)
• Mertens function returns 0
• Harshad number
• HTTP error code for Proxy authentication required

408 = 2³ × 3 × 17

• sum of four consecutive primes (97 + 101 + 103 + 107)
• sum of eight consecutive primes (37 + 41 + 43 + 47 + 53 + 59 + 61 + 67)
• Mertens function returns 0,
• octagonal number
• untouchable number
• Harshad number
• HTTP error code for Request timeout

409 is a prime number, Chen prime, centered triangular number. An octagonal number is a figurate number that represents an octagon. ... A centered triangular number is a centered figurate number that represents a triangle with a dot in the center and all other dots surrounding the center in successive triangular layers. ...

• A cleaning product 409®, see butoxyethanol
• There is also an automobile called the 409
• For the song about that car, see the group The Beach Boys.
• The year 409 or 409 BC
• HTTP error code for Conflict

410 = 2 × 5 × 41, sphenic number, sum of six consecutive primes (59 + 61 + 67 + 71 + 73 + 79), nontotient, Harshad number, HTTP error code for Gone 2-Butoxyethanol (CAS # 111-76-2, also known as ethylene glycol monobutyl ether, ethylene glycol butyl ether, ethylene glycol n-butyl ether, Butyl Cellusolve, butyl glycol, and butyl Oxitol; primary solvent in the Clorox Companys popular cleaning product 409®) is a versatile solvent. ... Jump to: navigation, search A small variety of cars, the most popular kind of automobile. ... The Beach Boys, 1963 (L to R, David Marks, Carl Wilson, Dennis Wilson, Mike Love, Brian Wilson) The Beach Boys are a pop music group formed in Hawthorne, California in 1961, whose popularity has lasted into the twenty-first century. ... For the cleaning product 409®, see butoxyethanol. ... Centuries: 6th century BC - 5th century BC - 4th century BC Decades: 450s BC 440s BC 430s BC 420s BC 410s BC - 400s BC - 390s BC 380s BC 370s BC 360s BC 350s BC Years: 414 BC 413 BC 412 BC 411 BC 410 BC - 409 BC - 408 BC 407 BC...

411 = 3 × 137, self number, HTTP error code for Length required

412 = 2² × 103, nontotient, noncototient, HTTP error code for recondition failed

413 = 7 × 59, Mertens function returns 0, self number, HTTP error code for Request entity too large

414 = 2 × 3² × 23, Mertens function returns 0, nontotient, Harshad number, HTTP error code for Request URI too long

415 = 5 × 83, it is also the area code for San Francisco, California, HTTP error code for Unsupported media type The downtown San Francisco skyline, looking east from the central part of the city. ...

416 = 2⁵ × 13, HTTP error code for Requested Range not satisfiable

417 = 3 × 139, HTTP error code for Expectation failed

418 = 2 × 11 × 19, sphenic number, also area code for Quebec Beginning in 1963, a terrorist group that became known as the Front de libération du Québec (FLQ) launched a decade of bombings, robberies and attacks on government offices and at least two murders by FLQ gunfire and three violent deaths by bombings. ...

419 prime number, Sophie Germain prime, Chen prime, Eisenstein prime with no imaginary part, highly cototient number, Mertens function returns 0 A prime number p is called a Sophie Germain prime if 2p + 1 is also prime. ... In number theory, a branch of mathematics, a highly cototient number k is an integer that has more solutions to the equation x - φ(x) = k, where φ is Eulers totient function, than any integer below it, with the exception of 1. ...

420 has its own page 420 is the natural number following 419 and preceding 421. ...

421 prime number, sum of five consecutive primes (73 + 79 + 83 + 89 + 97), centered square number, also SMTP code meaning the transmission channel will be closing A centered square number is a centered figurate number that represents a square with a dot in the center and all other dots surrounding the center up to a certain city block distance. ... Simple Mail Transfer Protocol (SMTP) is the de facto standard for email transmission across the Internet. ...

422 = 2 × 211, Mertens function returns 0, nontotient

423 = 3² × 47, Mertens function returns 0, Harshad number

424 = 2³ × 53, sum of ten consecutive primes (23 + 29 + 31 + 37 + 41 + 43 + 47 + 53 + 59 + 61), Mertens function returns 0, self number

425 = 5² × 17, sum of three consecutive primes (137 + 139 + 149), Mertens function returns 0

426 = 2 × 3 × 71, sphenic number, nontotient, untouchable number

427 = 7 × 61, Mertens function returns 0

428 = 2² × 107, Mertens function returns 0, nontotient

429 = 3 × 11 × 13, sphenic number, Catalan number In combinatorial mathematics, the Catalan numbers form a sequence of natural numbers that occur in various counting problems; which often have a recursive flavour. ...

430 = 2 × 5 × 43, sphenic number, untouchable number

431 prime number, Sophie Germain prime, sum of seven consecutive primes (47 + 53 + 59 + 61 + 67 + 71 + 73), Chen prime, Eisenstein prime with no imaginary part

432 sum of four consecutive primes (103 + 107 + 109 + 113), a highly totient number, and a Harshad number. A highly totient number k is an integer that has more solutions to the equation φ(x) = k, where φ is Eulers totient function, than any integer below it. ... A Harshad number, or Niven number, is an integer that is divisible by the sum of its digits in a given number base. ...

433 prime number, star number. The perfect score in the game show Fifteen To One, only ever achieved once in over 2000 shows. A star number, or centered 12-gonal number, is a centered figurate number that represents a centered hexagram, such as the one that Chinese checkers are played on. ... Fifteen to One was a popular general knowledge quiz show on Channel 4 in the United Kingdom, that ran from 4 January 1988 to 19 December 2003. ...

434 = 2 × 7 × 31, sphenic number, sum of six consecutive primes (61 + 67 + 71 + 73 + 79 + 83)nontotient

435 = 3 × 5 × 29, sphenic number, triangular number, hexagonal number, self number A hexagonal number is a figurate number that represents a hexagon. ...

436 = 2² × 109, nontotient, noncototient

437 = 19 × 23

438 = 2 × 3 × 73, sphenic number, Smith number A Smith number is a number which in a given base, the sum of its digits is equal to the sum of the digits in its factorization. ...

439 prime number, sum of three consecutive primes (139 + 149 + 151), sum of nine consecutive primes (31 + 37 + 41 + 43 + 47 + 53 + 59 + 61 + 67), strictly non-palindromic number

440 = 2³ × 5 × 11, the sum of the first seventeen prime numbers, Harshad number, also, in hertz, the standard frequency to which most orchestras tune the pitch A above middle C. A few orchestras tune slightly flatter or sharper than this. The hertz (symbol Hz) is the SI unit of frequency. ... Melbourne Symphony Orchestra Melbourne Symphony Orchestra Orchestra at City Hall (Edmonton). ...

441 = 3² × 7² = 21², sum of the cubes of the first natural numbers, centered octagonal number, Harshad number A centered octagonal number is a centered figurate number that represents an octagon with a dot in the center and all other dots surrounding the center dot in successive octagonal layers. ...

442 = 2 × 13 × 17, sphenic number, sum of eight consecutive primes (41 + 43 + 47 + 53 + 59 + 61 + 67 + 71)

443 prime number, Sophie Germain prime, Chen prime,+ Eisenstein prime with no imaginary part, Mertens function sets new low of -9, which stands until 659

444 = 2² × 3 × 37, Harshad number

445 = 5 × 89

446 = 2 × 223, nontotient, self number

447 = 3 × 149

448 = 2⁶ × 7, untouchable number, Harshad number

449 prime number, sum of five consecutive primes (79 + 83 + 89 + 97 + 101), Chen prime, Eisenstein prime with no imaginary part

450 = 2 × 3² × 5², nontotient, Harshad number, also SMTP code meaning the requested mail action was not carried out

451 Wedderburn-Etherington number; centered decagonal number; its reciprocal has period 10; 451 is the smallest number with this period reciprocal length. A Wedderburn-Etherington number counts how many weakly binary trees can be constructed such that each graph vertex (not counting the root vertex) is adjacent to no more than three other such vertices, for a given number of nodes. ... A centered decagonal number is a centered figurate number that represents a decagon with a dot in the center and all other dots surrounding the center dot in successive decagonal layers. ...

452 = 2² × 113, also SMTP code meaning that the requested mail action was not carried out because of insufficient system storage

453 = 3 × 151

454 = 2 × 227, nontotient, Smith number

455 = 5 × 7 × 13, sphenic number, tetrahedral number A tetrahedral number, or triangular pyramidal number, is a figurate number that represents a pyramid with a base and three sides, that is, a tetrahedron. ...

456 = 2³ × 3 × 19, sum of a twin prime (227 + 229), sum of four consecutive primes (107 + 109 + 113 + 127), centered pentagonal number A centered pentagonal number is a centered figurate number that represents a pentagon with a dot in the center and all other dots surrounding the center in successive pentagonal layers. ...

457 prime number, sum of three consecutive primes (149 + 151 + 157), self number

458 = 2 × 229, nontotient

459 = 3³ × 17

460 = 2² × 5 × 23, centered triangular number, Harshad number

461 prime number, Chen prime, Eisenstein prime with no imaginary part

462 = 2 × 3 × 7 × 11, sum of six consecutive primes (67 + 71 + 73 + 79 + 83 + 89), pronic number A pronic number, or oblong number or heteromecic number, is a number which is the product of two consecutive nonnegative integers, that is, n(n + 1). ...

463 prime number, sum of seven consecutive primes (53 + 59 + 61 + 67 + 71 + 73 + 79), centered heptagonal number A centered heptagonal number is a centered figurate number that represents a heptagon with a dot in the center and all other dots surrounding the center dot in successive heptagonal layers. ...

464 = 2⁴ × 29

See also: 4-6-4, the year AD 464. A 4-6-4 locomotive, in the Whyte notation for the classification of steam locomotives, has four leading wheels (generally arranged in a leading truck), six coupled driving wheels and four trailing wheels (often but not always in a trailing truck). ... For other uses, see number 464. ...

465 = 3 × 5 × 31, sphenic number, triangular number, Harshad number A sphenic number is a positive integer that is the product of three distinct prime factors. ...

466 = 2 × 233, noncototient

467 prime number, safe prime, Chen prime, Eisenstein prime with no imaginary part A safe prime is a prime number of the form 2p + 1, where p is also a prime. ...

468 = 2² × 3² × 13, sum of ten consecutive primes (29 + 31 + 37 + 41 + 43 + 47 + 53 + 59 + 61 + 67), self number, Harshad number

469 = 7 × 67, centered hexagonal number A centered hexagonal number, or hex number is a centered figurate number that represents a hexagon with a dot in the center and all other dots surrounding the center dot in successive hexagonal layers. ...

470 = 2 × 5 × 47, sphenic number, nontotient, noncototient

471 = 3 × 157, sum of three consecutive primes (151 + 157 + 163)

472 = 2³ × 59, nontotient, untouchable number

473 = 11 × 43, sum of five consecutive primes (83 + 89 + 97 + 101 + 103)

474 = 2 × 3 × 79, sphenic number, sum of eight consecutive primes (43 + 47 + 53 + 59 + 61 + 67 + 71 + 73), nontotient, noncototient, untouchable number, nonagonal number A nonagonal number or enneagonal number is a figurate number that represents a nonagon. ...

475 is a 49-gonal number; see also, Interstate 475 In mathematics, a polygonal number is a number that can be arranged as a regular polygon. ... Interstate 475 is the designation of several Interstate Highways in the United States, all of which are related to Interstate 75: Interstate 475 (Georgia), a bypass of Macon, Georgia. ...

476 = 2² × 7 × 17, Harshad number

477 = 3² × 53

478 = 2 × 239

479 prime number, safe prime, sum of nine consecutive primes (37 + 41 + 43 + 47 + 53 + 59 + 61 + 67 + 71), Chen prime, Eisenstein prime with no imaginary part, self number

480 = 2⁵ × 3 × 5, sum of a twin prime (239 + 241), sum of four consecutive primes (109 + 113 + 127 + 131), highly totient number, Harshad number

481 = 13 × 37, octagonal number, centered square number, Harshad number

482 = 2 × 241, nontotient, noncototient

483 = 3 × 7 × 23, sphenic number, Smith number

484 = 2² × 11² = 22², nontotient

485 = 5 × 97

486 = 2 × 3⁵, Harshad number, also shorthand for the Intel 80486 microprocessor chip An Intel i486 Microprocessor The Intel i486 (also called 486 or 80486) is a range of Intel CISC microprocessors which is part of the Intel x86 family of processors. ...

487 prime number, sum of three consecutive primes (157 + 163 + 167), Chen prime

488 = 2³ × 61, nontotient

489 = 3 × 163, octahedral number An octahedral number is a figurate number that represents an octahedron, or two pyramids placed together, one upside-down underneath the other. ...

490 = 2 × 5 × 7², noncototient, self number

491 prime number, Sophie Germain prime, Chen prime, Eisenstein prime with no imaginary part, strictly non-palindromic number

492 = 2² × 3 × 41, sum of six consecutive primes (71 + 73 + 79 + 83 + 89 + 97)

493 = 17 × 29, sum of seven consecutive primes (59 + 61 + 67 + 71 + 73 + 79 + 83)

494 = 2 × 13 × 19, sphenic number, nontotient

495 = 3² × 5 × 11, pentatope number, 51-gonal number, 166-gonal number. Also, 495 has the interesting property that if you start with a three digit number, arrange the digits in ascending order, then in descending order, subtracting the smaller number from the larger number and repeating the process eventually yields 495. A pentatope number is a number in the fifth cell of any row of Pascals triangle starting with the 5-term row 1 4 6 4 1 either from left to right or from right to left. ... In mathematics, a polygonal number is a number that can be arranged as a regular polygon. ...

496 now has its own article. Four hundred and ninety-six is the natural number following four hundred and ninety-five and preceding four hundred and ninety-seven. ...

497 = 7 × 71, sum of five consecutive primes (89 + 97 + 101 + 103 + 107)

498 = 2 × 3 × 83, sphenic number, untouchable number

499 prime number, Chen prime