No, 221 is not a prime number. It is a composite number: 221 = 13 × 17.
221 has divisors other than 1 and itself. The smallest is 13: 221 ÷ 13 = 17.
Prime factorization: 221 = 13 × 17.
| Number | Prime? |
|---|---|
| 217 | No, 7 × 31 |
| 218 | No, 2 × 109 |
| 219 | No, 3 × 73 |
| 220 | No, 2 × 2 × 5 × 11 |
| 222 | No, 2 × 3 × 37 |
| 223 | Yes |
| 224 | No, 2 × 2 × 2 × 2 × 2 × 7 |
| 225 | No, 3 × 3 × 5 × 5 |
More about 221: 221 in binary.
Another number? Use the prime number checker for any value, or see the list of prime numbers.