No, 66 is not a prime number. It is a composite number: it is even, so it is divisible by 2.
66 has divisors other than 1 and itself. The smallest is 2: 66 ÷ 2 = 33.
Prime factorization: 66 = 2 × 3 × 11.
| Number | Prime? |
|---|---|
| 62 | No, 2 × 31 |
| 63 | No, 3 × 3 × 7 |
| 64 | No, 2 × 2 × 2 × 2 × 2 × 2 |
| 65 | No, 5 × 13 |
| 67 | Yes |
| 68 | No, 2 × 2 × 17 |
| 69 | No, 3 × 23 |
| 70 | No, 2 × 5 × 7 |
More about 66: factors of 66 · 66 squared · square root of 66 · 66 in binary · 66 in Roman numerals.
Another number? Use the prime number checker for any value, or see the list of prime numbers.