Twelve (12) is the natural number following eleven and preceding thirteen.
Twelve is a composite number, its proper divisors being 1, 2, 3, 4 and 6. Twelve is also a highly composite number, the next one being 24[?].
A twelve-sided polygon is a dodecagon. A twelve-sided polyhedron is a dodecahedron.
The number twelve is often used as a sales unit in trade, and is often referred to as a dozen. Twelve dozen are known as a gross. Note that there are thirteen loaves in a baker's dozen.
There are twelve months in a year.
The duodecimal system, which is the use of 12 as a division factor for many historical weights and measures, including hours, probably originates from Mesopotamia. See also: base 12.
In the United States, juries deciding legal cases typically have twelve members.
