Yes, 131 is a prime number. Its only factors are 1 and 131.
A number is prime if no smaller prime up to its square root divides it. The square root of 131 is about 11.45, so it is enough to test the primes 2, 3, 5, 7 and 11.
| Divide by | Remainder | Divides evenly? |
|---|---|---|
| 2 | 1 | No |
| 3 | 2 | No |
| 5 | 1 | No |
| 7 | 5 | No |
| 11 | 10 | No |
None of them divides 131 evenly, so 131 is prime.
| Number | Prime? |
|---|---|
| 127 | Yes |
| 128 | No, 2 × 2 × 2 × 2 × 2 × 2 × 2 |
| 129 | No, 3 × 43 |
| 130 | No, 2 × 5 × 13 |
| 132 | No, 2 × 2 × 3 × 11 |
| 133 | No, 7 × 19 |
| 134 | No, 2 × 67 |
| 135 | No, 3 × 3 × 3 × 5 |
More about 131: factors of 131 · 131 squared · square root of 131 · 131 in binary · 131 in Roman numerals.
Another number? Use the prime number checker for any value, or see the list of prime numbers.