Factors of 31
Every whole number that divides 31 exactly, the factor pairs, and how to find them yourself.
The answer
The factors of 31 are 1 and 31. 31 is a prime number.
Factor pairs of 31
| Pair | Makes |
|---|---|
| 1 × 31 | 31 |
Prime factors of 31
- Prime factorisation
- 31 = 31
- Is 31 prime?
- Yes. It is the 11th prime number.
- Is 31 a square number?
- No. 5 × 5 = 25 and 6 × 6 = 36, so 31 falls between two square numbers.
How to find the factors of 31
31 is prime, so the only pair you will find is 1 × 31. Work up from 1 to 5, and write down both numbers in every pair you find.
- 31 ÷ 1 = 31, so 1 × 31 is a pair.
- 2 does not go into 31 exactly.
- 3 does not go into 31 exactly.
- 4 does not go into 31 exactly.
- 5 does not go into 31 exactly.
Stop at 6: 6 × 6 = 36, which is more than 31. The next pair you would find is 31 × 1, which is 1 × 31 turned round, so you already have every pair.
More numbers
Check whether 31 is prime.
Questions parents ask
What is the largest factor of 31, apart from 31 itself?
1. 31 is prime, so apart from 31 itself its only factor is 1.
What do the factors of 31 add up to?
32. Leaving out 31 itself, they add up to 1, which is less than 31, so 31 is called a deficient number.
Which number after 31 has the same number of factors?
37. Like 31, it has exactly 2 factors.
Continue your number practice
Explore the diagnostic for another set of practice questions.