Is 403 a prime number?

No, 403 is not a prime number. It is a composite number: 403 = 13 × 31.

Why 403 is not prime

403 has divisors other than 1 and itself. The smallest is 13: 403 ÷ 13 = 31.

Prime factorization: 403 = 13 × 31.

Quick facts about 403

Is it prime? Nearby numbers

NumberPrime?
399No, 3 × 7 × 19
400No, 2 × 2 × 2 × 2 × 5 × 5
401Yes
402No, 2 × 3 × 67
404No, 2 × 2 × 101
405No, 3 × 3 × 3 × 3 × 5
406No, 2 × 7 × 29
407No, 11 × 37

Another number? Use the prime number checker for any value, or see the list of prime numbers.