Factors of 27
Every whole number that divides 27 exactly, the factor pairs, and how to find them yourself.
The answer
The factors of 27 are 1, 3, 9 and 27.
Factor pairs of 27
| Pair | Makes |
|---|---|
| 1 × 27 | 27 |
| 3 × 9 | 27 |
Prime factors of 27
- Prime factorisation
- 27 = 3 × 3 × 3 (3³)
- Reading index form
- A small raised number tells you how many times to use that factor. For example, 2³ means 2 × 2 × 2.
- Is 27 prime?
- No. It has 4 factors, not just 1 and 27.
- Is 27 a square number?
- No. 5 × 5 = 25 and 6 × 6 = 36, so 27 falls between two square numbers.
How to find the factors of 27
27 is odd, so every even number you try will fail. Its digits add up to 9, a multiple of 9, so 3 and 9 are factors. Work up from 1 to 5, and write down both numbers in every pair you find.
- 27 ÷ 1 = 27, so 1 × 27 is a pair.
- 2 does not go into 27 exactly.
- 27 ÷ 3 = 9, so 3 × 9 is a pair.
- 4 does not go into 27 exactly.
- 5 does not go into 27 exactly.
Stop at 6: 6 × 6 = 36, which is more than 27. The next pair you would find is 9 × 3, which is 3 × 9 turned round, so you already have every pair.
27 in the times tables
3 × 9 = 27. Practise the 3 times table and 9 times table.
More numbers
Check whether 27 is prime.
Questions parents ask
What is the largest factor of 27, apart from 27 itself?
9. Divide 27 by its smallest factor above 1, which is 3: 27 ÷ 3 = 9.
What do the factors of 27 add up to?
40. Leaving out 27 itself, they add up to 13, which is less than 27, so 27 is called a deficient number.
Which number after 27 has the same number of factors?
33. Like 27, it has exactly 4 factors.
Continue your number practice
Explore the diagnostic for another set of practice questions.