No, 225 is not a prime number. It is a composite number: it ends in 5, so it is divisible by 5.
225 has divisors other than 1 and itself. The smallest is 3: 225 ÷ 3 = 75.
Prime factorization: 225 = 3 × 3 × 5 × 5 = 3² × 5².
| Number | Prime? |
|---|---|
| 221 | No, 13 × 17 |
| 222 | No, 2 × 3 × 37 |
| 223 | Yes |
| 224 | No, 2 × 2 × 2 × 2 × 2 × 7 |
| 226 | No, 2 × 113 |
| 227 | Yes |
| 228 | No, 2 × 2 × 3 × 19 |
| 229 | Yes |
More about 225: factors of 225 · square root of 225 · 225 in binary.
Another number? Use the prime number checker for any value, or see the list of prime numbers.