Factors of 42
Every whole number that divides 42 exactly, the factor pairs, and how to find them yourself.
The answer
The factors of 42 are 1, 2, 3, 6, 7, 14, 21 and 42.
Factor pairs of 42
| Pair | Makes |
|---|---|
| 1 × 42 | 42 |
| 2 × 21 | 42 |
| 3 × 14 | 42 |
| 6 × 7 | 42 |
Prime factors of 42
- Prime factorisation
- 42 = 2 × 3 × 7
- Is 42 prime?
- No. It has 8 factors, not just 1 and 42.
- Is 42 a square number?
- No. 6 × 6 = 36 and 7 × 7 = 49, so 42 falls between two square numbers.
How to find the factors of 42
42 is even, so 2 is sure to be a factor. Its digits add up to 6, a multiple of 3, so 3 is a factor. Work up from 1 to 6, and write down both numbers in every pair you find.
- 42 ÷ 1 = 42, so 1 × 42 is a pair.
- 42 ÷ 2 = 21, so 2 × 21 is a pair.
- 42 ÷ 3 = 14, so 3 × 14 is a pair.
- 4 does not go into 42 exactly.
- 5 does not go into 42 exactly.
- 42 ÷ 6 = 7, so 6 × 7 is a pair.
Stop at 7: 7 × 7 = 49, which is more than 42. The next pair you would find is 7 × 6, which is 6 × 7 turned round, so you already have every pair.
42 in the times tables
3 × 14 = 42 and 6 × 7 = 42. Practise the 6 times table, 7 times table and 14 times table.
More numbers
Check whether 42 is prime.
Questions parents ask
What is the largest factor of 42, apart from 42 itself?
21. Divide 42 by its smallest factor above 1, which is 2: 42 ÷ 2 = 21.
What do the factors of 42 add up to?
96. Leaving out 42 itself, they add up to 54, which is more than 42, so 42 is called an abundant number.
Which number after 42 has the same number of factors?
54. Like 42, it has exactly 8 factors.
Number facts are the base of 11+ maths
Factors, multiples, primes and square numbers come up all over 11+ maths, from simplifying fractions to ratio. The free diagnostic checks maths, English and both kinds of reasoning, and shows what to practise next. No card is required.