Factors, Prime Factors and Highest Common Factor (HCF)

Definition of factor

A whole number that divides a number exactly

The factors of 18

1, 2, 3, 6, 9 and 18

Definition of a prime number

A number that can be divided exactly by 1 and by the number itself

Definition of prime factor

The factor that is a prime number

Definition of prime factorisation

The process of expressing a number as a product of the multiplication of its prime factors

Definition of common factor

A number that divides exactly two or more other numbers

A common factor for all numbers

1

The common factors of 6 and 30

1, 2, 3 and 6

Definition of highest common factor (HCF) of two numbers

Common factor for two numbers with the largest value

HCF for 6 and 30

6