Factors, multiples and primes

A factor of a number divides it exactly. The factors of 12 are $1, 2, 3, 4, 6$ and $12$. A multiple of 12 is what you get by multiplying 12 by a whole number: $12, 24, 36, \dots$

Prime numbers

Prime factors

Every whole number greater than 1 can be written as a product of primes in only one way, apart from the order. We find it by dividing by primes again and again.

Try it yourself