Open main menu


A 1 is a positive prime natural number preceded by 0 and followed by 2.



  • (Wikipedia, 2020) ⇒ Retrieved:2020-3-14.
    • 1 (one, also called unit, and unity) is a number, and a numerical digit used to represent that number in numerals. It represents a single entity, the unit of counting or measurement. For example, a line segment of unit length is a line segment of length 1. 1 is the smallest positive integer. It is also sometimes considered the first of the infinite sequence of natural numbers, followed by 2, although by other definitions 1 is the second natural number, following 0.

      The fundamental mathematical property of 1 is to be a multiplicative identity, meaning that any number multiplied by 1 returns that number. Most if not all properties of 1 can be deduced from this. In advanced mathematics, a multiplicative identity is often denoted 1, even if it is not a number. 1 is by convention not considered a prime number; although universal today, this was a matter of some controversy until the mid-20th century.