Is 231 a prime number?
No, 231 is not a prime number. It is divisible by 3: 231 = 3 × 77.
Is 231 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 √231 ≈ 15.20. If none of them divides 231, it is prime.
- 3
3 divides 231 exactly, so it is not prime. Its prime factorisation is
LaTeX source of the formulas on this page
\[ 231 = 3 \times 7 \times 11 \]
Testing 231 by the primes up to its square root
| Prime | Division | Result |
|---|---|---|
| 2 | 231 ÷ 2 | leaves 1 |
| 3 | 231 ÷ 3 | divides exactly (77) |
| 5 | 231 ÷ 5 | leaves 1 |
| 7 | 231 ÷ 7 | divides exactly (33) |
| 11 | 231 ÷ 11 | divides exactly (21) |
| 13 | 231 ÷ 13 | leaves 10 |
Questions
Is 231 a prime number?
No, 231 is not a prime number. It is divisible by 3: 231 = 3 × 77.
What is the next prime after 231?
233.
What is the prime number before 231?
229.
What are the factors of 231?
1, 3, 7, 11, 21, 33, 77, 231.