60 is the natural number following 59 and preceding 61.

In mathematics

Sixty is a composite number with divisors 1, 2, 3, 4, 5, 6, 10, 12, 15, 20, 30, making it also a highly composite number. Because 60 is the sum of its unitary divisors (excluding itself), it is a unitary perfect number. And because it is divisible by the sum of its digits in base 10, it is a Harshad number. 60 is the smallest number divisible by the numbers 1 to 6. (There is no smaller number divisible by the numbers 1 to 5).

This number is the sum of a pair of twin primes (29 + 31), as well as the sum of four consecutive primes (11 + 13 + 17 + 19).

The smallest non-abelian simple group has order 60.

In normal space, the 3 interior angles of an equilateral triangle each measure 60 degrees, adding up to 180 degrees.

The Babylonian number system had a base of sixty. A number system with base sixty is called a sexagesimal number system.

The Sexigesimal cycle plays a role in Chinese numbering and numerology.

In science

• The atomic number of neodymium, a lanthanide

In astronomy,

Messier object M60, a magnitude 10.5 galaxy in the constellation Virgo

The New General Catalogue object (http://www.ngcic.org/) NGC 60, a spiral galaxy in the constellation Pisces

The Saros number (http://sunearth.gsfc.nasa.gov/eclipse/SEsaros/SEsaros1-175.html) of the solar eclipse series which began on -1020 May 18 and ended on 260 June 26. The duration of Saros series 60 was 1280.1 years, and it contained 72 solar eclipses.

The Saros number (http://sunearth.gsfc.nasa.gov/eclipse/LEsaros/LEsaros1-175.html) of the lunar eclipse series which began on -700 March 8 and ended on 616 May 7. The duration of Saros series 60 was 1316.2 years, and it contained 74 lunar eclipses.

In other fields

Sixty is also:

• in the measurement of time, the number of seconds in a minute, and the number of minutes in an hour.
• in geometry, the number of seconds in a minute, and the number of minutes in a degree.
• a common speed limit, in miles per hour, for freeways in many US states.
• in years of marriage, the diamond wedding anniversary.
• the maximum number of marbles (game pieces) in Chinese checkers.
• the code for international direct dial calls to Malaysia.
• The year AD 60, 60 BC, or 1960.