The number 57 has four factors. These are 1, 3, 19 and 57. Factors of a number are numbers that can be multiplied to equal the given number.
A prime number only has two factors. By definition, a prime number can only be divided evenly by the number 1 and itself, resulting in only two numbers being able to be multiplied together to reach the given number. A composite number is a number that has at least two more numbers that can be evenly multiplied to reach the given number.
Prime factorization is defined as listing all of the prime number factors of the given number.