No, 400 is not a prime number. It is a composite number: it is even, so it is divisible by 2.
400 has divisors other than 1 and itself. The smallest is 2: 400 ÷ 2 = 200.
Prime factorization: 400 = 2 × 2 × 2 × 2 × 5 × 5 = 2⁴ × 5².
| Number | Prime? |
|---|---|
| 396 | No, 2 × 2 × 3 × 3 × 11 |
| 397 | Yes |
| 398 | No, 2 × 199 |
| 399 | No, 3 × 7 × 19 |
| 401 | Yes |
| 402 | No, 2 × 3 × 67 |
| 403 | No, 13 × 31 |
| 404 | No, 2 × 2 × 101 |
More about 400: factors of 400 · 400 squared · square root of 400 · 400 in binary · 400 in Roman numerals.
Another number? Use the prime number checker for any value, or see the list of prime numbers.