# Prime number

From 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 satisfying the following equivalent conditions:

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