Is 31 a prime number?
Yes, 31 is a prime number. Its only factors are 1 and 31.
Is 31 prime?
Pick any whole number from 1 to 10,000.
How to work it out
- 1
A prime number has exactly two factors: 1 and itself.
- 2
It is enough to test the primes up to √31 ≈ 5.57. If none of them divides 31, it is prime.
- 3
None of them divides 31, so it is prime.
Testing 31 by the primes up to its square root
| Prime | Division | Result |
|---|---|---|
| 2 | 31 ÷ 2 | leaves 1 |
| 3 | 31 ÷ 3 | leaves 1 |
| 5 | 31 ÷ 5 | leaves 1 |
Questions
Is 31 a prime number?
Yes, 31 is a prime number. Its only factors are 1 and 31.
What is the next prime after 31?
37.
What is the prime number before 31?
29.
What are the factors of 31?
1, 31.