No, 25 is not a prime number. It is a composite number: it ends in 5, so it is divisible by 5.
25 has divisors other than 1 and itself. The smallest is 5: 25 ÷ 5 = 5.
Prime factorization: 25 = 5 × 5 = 5².
| Number | Prime? |
|---|---|
| 21 | No, 3 × 7 |
| 22 | No, 2 × 11 |
| 23 | Yes |
| 24 | No, 2 × 2 × 2 × 3 |
| 26 | No, 2 × 13 |
| 27 | No, 3 × 3 × 3 |
| 28 | No, 2 × 2 × 7 |
| 29 | Yes |
More about 25: factors of 25 · 25 squared · square root of 25 · 25 in binary · 25 in Roman numerals.
Another number? Use the prime number checker for any value, or see the list of prime numbers.