Factors of 55
Every whole number that divides 55 exactly, the factor pairs, and how to find them yourself.
The answer
The factors of 55 are 1, 5, 11 and 55.
Factor pairs of 55
| Pair | Makes |
|---|---|
| 1 × 55 | 55 |
| 5 × 11 | 55 |
Prime factors of 55
- Prime factorisation
- 55 = 5 × 11
- Is 55 prime?
- No. It has 4 factors, not just 1 and 55.
- Is 55 a square number?
- No. 7 × 7 = 49 and 8 × 8 = 64, so 55 falls between two square numbers.
How to find the factors of 55
55 is odd, so every even number you try will fail. It ends in 5, so 5 is a factor. Work up from 1 to 7, and write down both numbers in every pair you find.
- 55 ÷ 1 = 55, so 1 × 55 is a pair.
- 2 does not go into 55 exactly.
- 3 does not go into 55 exactly.
- 4 does not go into 55 exactly.
- 55 ÷ 5 = 11, so 5 × 11 is a pair.
- 6 does not go into 55 exactly.
- 7 does not go into 55 exactly.
Stop at 8: 8 × 8 = 64, which is more than 55. The next pair you would find is 11 × 5, which is 5 × 11 turned round, so you already have every pair.
55 in the times tables
5 × 11 = 55. Practise the 5 times table and 11 times table.
More numbers
Check whether 55 is prime.
Questions parents ask
What is the largest factor of 55, apart from 55 itself?
11. Divide 55 by its smallest factor above 1, which is 5: 55 ÷ 5 = 11.
What do the factors of 55 add up to?
72. Leaving out 55 itself, they add up to 17, which is less than 55, so 55 is called a deficient number.
Which number after 55 has the same number of factors?
57. Like 55, it has exactly 4 factors.
Continue your number practice
Explore the diagnostic for another set of practice questions.