﻿ What is a composite number? Explained with examples and non examples. # What is a composite Number?

A composite number is a positive integer that has a factor other than 1 and itself. For instance, 6 is a composite number because:

• it is positive
• it has a factor other than 1 and itself (both 2 and 3 are factors of 6)

If you are familiar with prime numbers, then you should recognize that a positive integer is either prime or composite--these two terms are mutually exclusive.

### Examples of Composite Numbers

• 4
• 4 is composite because 2 is a factor
• 8
• 8 is a composite number because it has 4 and 2 as factors

### Non examples of Composite Numbers

• 5
• 5 is not a composite number because its only factors are 1 and itself (5). 5 is, however, a prime number.
• 2
• 2 is not a composite number because its only factors are 1 and itself (2). 2 is, however, a prime number. 2 is also the even number that is not composite. Every other even number is indeed a composite number.
• 7
• 7 is not a composite number because its only factors are 1 and itself (7). 7 is, however, a prime number.