168 is the natural number following 167 and preceding 169. 167 is the natural number following 166 and preceding 168. ... 169 is the natural number following one hundred sixty-eight and preceding one hundred seventy. ...

List of numbers — Integers << 160 161 162 163 164 165 166 167 168 169 >> This is a list of articles about numbers (not about numerals). ... The integers are commonly denoted by the above symbol. ... Cardinal one hundred fifty-nine Ordinal 159th (one hundred fifty-ninth) Factorization Divisors 3, 53 Roman numeral CLIX Binary 10111111 Hexadecimal 9F 159 is a natural number following 158 and preceding 160. ... 160 is the natural number following one hundred fifty-nine and preceding one hundred sixty-one. ... Cardinal one hundred and sixty-one Ordinal 161st (one hundred and sixty-first) Factorization Divisors 7, 23 Roman numeral CLXI Binary 10100001 Hexadecimal A1 161 is an odd natural number between 160 and 162. ... Cardinal one hundred and sixty-two Ordinal 162nd (one hundred and sixty-second) Factorization Divisors 1, 2, 9, 81 Roman numeral CLXII Binary 10100010 Hexadecimal A2 162 is an even natural number between 161 and 163. ... 163 is the natural number following one hundred sixty-two and preceding one hundred sixty-four. ... 164 (one hundred (and) sixty-four) is the natural number following 163 and preceding 165. ... 165 is the natural number following 164 and preceding 166. ... 166 is the natural number following one hundred (and) sixty-five and preceding one hundred (and) sixty-seven. ... 167 is the natural number following 166 and preceding 168. ... 169 is the natural number following one hundred sixty-eight and preceding one hundred seventy. ... 170 is the natural number following 169 and preceding 171. ...
Cardinal	One hundred [and] sixty-eight
Ordinal	168th
Factorization
Roman numeral	CLXVIII
Binary	10101000
Hexadecimal	A8

It is the sum of four consecutive primes (37 + 41 + 43 + 47). Aleph-0, the smallest infinite cardinal In mathematics, cardinal numbers, or cardinals for short, are a generalized kind of number used to denote the size of a set. ... 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. ... The binary numeral system, or base-2 number system, is a numeral system that represents numeric values using two symbols, usually 0 and 1. ... In mathematics and computer science, hexadecimal, base-16, 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. ...

168 is the order of the group PSL(2,7), the second smallest nonabelian simple group. From Hurwitz's automorphisms theorem we know that 168 is the maximum possible number of automorphisms of a genus 3 Riemann surface, this maximum being achieved by the Klein quartic, whose symmetry group is PSL(2,7). The Fano plane has 168 symmetries, and again the symmetry group is PSL(2,7). The projective special linear group G = PSL(2,7) is a finite group in mathematics that has important applications in algebra, geometry, and number theory. ... In mathematics, Hurwitzs automorphisms theorem bounds the group of automorphisms, via conformal mappings, of a compact Riemann surface of genus g > 1, telling us that the order of the group of such automorphisms is bounded by 84(g − 1). ... Riemann surface for the function f(z) = sqrt(z) In mathematics, particularly in complex analysis, a Riemann surface, named after Bernhard Riemann, is a one-dimensional complex manifold. ... The Klein quartic x3y + y3z + z3x = 0, named after Felix Klein, is a Riemann surface, and a curve of genus 3 over the complex numbers C. The Klein quartic has automorphism group isomorphic to the projective special linear group G = PSL(2,7). ... A finite geometry is any geometric system that has only a finite number of points. ...

One hundred sixty-eight is also:

• The year AD 168 or 168 BC.
• The number of hours in a week.
• The total number of pips on a standard domino set.

// Events Change of Han Huandi to Han Lingdi of Han Dynasty; first year of Jianning era. ... Centuries: 3rd century BC - 2nd century BC - 1st century BC Decades: 210s BC 200s BC 190s BC 180s BC 170s BC - 160s BC - 150s BC140s BC 130s BC 120s BC 110s BC Years: 173 BC 172 BC 171 BC 170 BC 169 BC - 168 BC - 167 BC 166 BC 165... The hour (symbol: h) is a unit of time. ... For the TV station in the Peoria-Bloomington, Illinois market, see WEEK-TV. A week is a unit of time longer than a day and shorter than a month. ... Domino redirects here—for other meanings of the word, see Domino (disambiguation). ...

References

• This Week's Finds in Mathematical Physics 214, John Baez