In mathematics, natural numbers, also known as counting numbers, are either the set positive integers (1, 2, 3, …) or the set of non-negative numbers (0, 1, 2, …). The set of natural numbers are usually denoted N or 
.
In mathematics, natural numbers, also known as counting numbers, are either the set positive integers (1, 2, 3, …) or the set of non-negative numbers (0, 1, 2, …). The set of natural numbers are usually denoted N or .