Prime number

This article defines a property that can be evaluated for a natural number, i.e., every natural number either satisfies the property or does not satisfy the property.
View a complete list of properties of natural numbers

Definition

A prime number is a natural number greater than $1$ satisfying the following equivalent conditions:

• It has exactly two positive divisors: itself and $1$.
• It is a prime element in the ring of integers.
• It is relatively prime to all the numbers less than itself.