Yes, 149 is a prime number. Its only factors are 1 and 149.
A number is prime if no smaller prime up to its square root divides it. The square root of 149 is about 12.21, 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 | 4 | No |
| 7 | 2 | No |
| 11 | 6 | No |
None of them divides 149 evenly, so 149 is prime.
| Number | Prime? |
|---|---|
| 145 | No, 5 × 29 |
| 146 | No, 2 × 73 |
| 147 | No, 3 × 7 × 7 |
| 148 | No, 2 × 2 × 37 |
| 150 | No, 2 × 3 × 5 × 5 |
| 151 | Yes |
| 152 | No, 2 × 2 × 2 × 19 |
| 153 | No, 3 × 3 × 17 |
More about 149: factors of 149 · 149 squared · square root of 149 · 149 in binary · 149 in Roman numerals.
Another number? Use the prime number checker for any value, or see the list of prime numbers.