What is a composite number?

A composite number is a whole number greater than 1 that has factors other than just 1 and itself, so it can be divided evenly in more than one way. Every whole number over 1 is either prime (exactly two factors) or composite (more than two).

Examples

• 8 is composite because its factors are 1, 2, 4 and 8.
• 9 is composite (3 × 3 = 9).
• The first composite numbers are 4, 6, 8, 9, 10.

Quick facts

• 1 is neither prime nor composite, it has only one factor.
• 2 is the smallest prime, and 4 is the smallest composite number.