No, 166 is not a prime number. It is a composite number: it is even, so it is divisible by 2.
166 has divisors other than 1 and itself. The smallest is 2: 166 ÷ 2 = 83.
Prime factorization: 166 = 2 × 83.
| Number | Prime? |
|---|---|
| 162 | No, 2 × 3 × 3 × 3 × 3 |
| 163 | Yes |
| 164 | No, 2 × 2 × 41 |
| 165 | No, 3 × 5 × 11 |
| 167 | Yes |
| 168 | No, 2 × 2 × 2 × 3 × 7 |
| 169 | No, 13 × 13 |
| 170 | No, 2 × 5 × 17 |
More about 166: factors of 166 · square root of 166 · 166 in binary.
Another number? Use the prime number checker for any value, or see the list of prime numbers.