Yes, 47 is a prime number. Its only factors are 1 and 47.
A number is prime if no smaller prime up to its square root divides it. The square root of 47 is about 6.86, so it is enough to test the primes 2, 3 and 5.
| Divide by | Remainder | Divides evenly? |
|---|---|---|
| 2 | 1 | No |
| 3 | 2 | No |
| 5 | 2 | No |
None of them divides 47 evenly, so 47 is prime.
| Number | Prime? |
|---|---|
| 43 | Yes |
| 44 | No, 2 × 2 × 11 |
| 45 | No, 3 × 3 × 5 |
| 46 | No, 2 × 23 |
| 48 | No, 2 × 2 × 2 × 2 × 3 |
| 49 | No, 7 × 7 |
| 50 | No, 2 × 5 × 5 |
| 51 | No, 3 × 17 |
More about 47: factors of 47 · 47 squared · square root of 47 · 47 in binary · 47 in Roman numerals.
Another number? Use the prime number checker for any value, or see the list of prime numbers.