How to find prime factors of a number?
To find the prime factors of a number we can repeatedly divide by prime numbers. For example to find the prime factors of 36, we would do the folowing steps. • Divide 36 by the smallest prime number, that is, divide 36 by 2 36 ÷ 2 = 18 • Now since 18 is divisible by 2, divide 18 by 2 18 ÷ 2 = 9 • 9 is not divisible by 2, so try to divide it by the next prime number, that is 3 9 ÷ 3 = 3 • 3 is a prime number, so we can stop here. And the prime factors are the ones that we have used in the divisions above including the last prime number that we got as a result of the division(the ones in bold) So, 36 = 2 × 2 × 3 × 3 Or in index notation: 36 = 22 × 32 Another example to find the prime factors of 42.
