12 (twelve) is the natural number following 11 and preceding 13. The product of the first 3 factorials, twelve is a superior highly composite number, divisible by 2, 3, 4, and 6. It is the number of years required for a full cycle of Jupiter, historically considered to be the brightest "wandering star". It is central to many systems of timekeeping, including the Western calendar and units of time of day, and frequently appears in the world's major religions.

Natural Numbers 0-20

In mathematics, natural numbers are those used for counting and ordering.

Some authors begin the natural numbers with 0, corresponding to the non-negative integers 0, 1, 2, 3, and others start with 1, corresponding to the positive integers 1, 2, 3, etc...

Properties of the natural numbers, such as divisibility and the distribution of prime numbers, are studied in number theory. Problems concerning counting and ordering, such as partitioning and enumerations, are studied in combinatorics.