Prime numbers

What is a prime number?

A prime number is any number which only has two factors: 1 and itself.

Examples of prime numbers

(factors: , )
(factors: , )
(factors: , )
(factors: , )
(factors: , )

Non-examples of prime numbers

(factors: , , ) - three factors
(factors: , , , ) - four factors
(factors: , , ) - three factors
(factors: , , , ) - four factors
(factors: ) - only one factor
- not prime as it is not an integer (whole number)

Composite numbers

You may think that all non-prime numbers are composite numbers, and you’d be right… usually.

The number has only one factor: , so it is not prime because it does not have 2 factors.
It is also not composite, because composite numbers have more than 2 factors.