50 (fifty) is the natural number following 49 and preceding 51.

Numbers in Tens to One Hundred

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, ..., whereas others start with 1, corresponding to the positive integers 1, 2, 3,...

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.