A composite number is a positive whole number that can be divided evenly by a number other than itself and one. For example, 12 is a composite number, as it can be divided evenly by three and four.
All whole numbers greater than zero are either prime numbers or composite numbers. A prime number can only be divided evenly by itself and one, whereas a composite number can also be divided evenly by a third number. The first four composite numbers counting from zero are four, six, eight and nine. Each composite number is also the product of two or more prime numbers.