Factors of 66
Every whole number that divides 66 exactly, the factor pairs, and how to find them yourself.
The answer
The factors of 66 are 1, 2, 3, 6, 11, 22, 33 and 66.
Factor pairs of 66
| Pair | Makes |
|---|---|
| 1 × 66 | 66 |
| 2 × 33 | 66 |
| 3 × 22 | 66 |
| 6 × 11 | 66 |
Prime factors of 66
- Prime factorisation
- 66 = 2 × 3 × 11
- Is 66 prime?
- No. It has 8 factors, not just 1 and 66.
- Is 66 a square number?
- No. 8 × 8 = 64 and 9 × 9 = 81, so 66 falls between two square numbers.
How to find the factors of 66
66 is even, so 2 is sure to be a factor. Its digits add up to 12, a multiple of 3, so 3 is a factor. Work up from 1 to 8, and write down both numbers in every pair you find.
- 66 ÷ 1 = 66, so 1 × 66 is a pair.
- 66 ÷ 2 = 33, so 2 × 33 is a pair.
- 66 ÷ 3 = 22, so 3 × 22 is a pair.
- 4 does not go into 66 exactly.
- 5 does not go into 66 exactly.
- 66 ÷ 6 = 11, so 6 × 11 is a pair.
- 7 does not go into 66 exactly.
- 8 does not go into 66 exactly.
Stop at 9: 9 × 9 = 81, which is more than 66. The next pair you would find is 11 × 6, which is 6 × 11 turned round, so you already have every pair.
66 in the times tables
6 × 11 = 66. Practise the 6 times table and 11 times table.
More numbers
Check whether 66 is prime.
Questions parents ask
What is the largest factor of 66, apart from 66 itself?
33. Divide 66 by its smallest factor above 1, which is 2: 66 ÷ 2 = 33.
What do the factors of 66 add up to?
144. Leaving out 66 itself, they add up to 78, which is more than 66, so 66 is called an abundant number.
Which number after 66 has the same number of factors?
70. Like 66, 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.