No, 279 is not a prime number. It is a composite number: its digits add up to 18, which is divisible by 3, so 279 is divisible by 3.
279 has divisors other than 1 and itself. The smallest is 3: 279 ÷ 3 = 93.
Prime factorization: 279 = 3 × 3 × 31 = 3² × 31.
| Number | Prime? |
|---|---|
| 275 | No, 5 × 5 × 11 |
| 276 | No, 2 × 2 × 3 × 23 |
| 277 | Yes |
| 278 | No, 2 × 139 |
| 280 | No, 2 × 2 × 2 × 5 × 7 |
| 281 | Yes |
| 282 | No, 2 × 3 × 47 |
| 283 | Yes |
Another number? Use the prime number checker for any value, or see the list of prime numbers.