When factoring, each factor that is a prime number.
Examples
- In the decomposition of the number 44, which is 44 = 2 × 2 × 11, the numbers 2 and 11 are prime factors.
- In the decomposition of the number 20, which is 20 = 22 × 5, the numbers 2 and 5 are prime factors.
- In the decomposition of the number 20, which is 20 = 4 × 5, the number 5 is a prime factor.