No, 721 is not a prime number. It is a composite number: 721 = 7 × 103.
721 has divisors other than 1 and itself. The smallest is 7: 721 ÷ 7 = 103.
Prime factorization: 721 = 7 × 103.
| Number | Prime? |
|---|---|
| 611 | No, 13 × 47 |
| 641 | Yes |
| 701 | Yes |
| 713 | No, 23 × 31 |
| 743 | Yes |
| 771 | No, 3 × 257 |
| 791 | No, 7 × 113 |
| 801 | No, 3 × 3 × 89 |
Another number? Use the prime number checker for any value, or see the list of prime numbers.