# Is 66 a prime number?

It is possible to find out using mathematical methods whether a given integer is a prime number or not.

For 66, the answer is: No, 66 is not a prime number.

The list of all positive divisors (i.e., the list of all integers that divide 66) is as follows: 1, 2, 3, 6, 11, 22, 33, 66.

For 66 to be a prime number, it would have been required that 66 has only two divisors, i.e., itself and 1.

Find out more:

As a consequence:

- 66 is a multiple of 1
- 66 is a multiple of 2
- 66 is a multiple of 3
- 66 is a multiple of 6
- 66 is a multiple of 11
- 66 is a multiple of 22
- 66 is a multiple of 33

For 66 to be a prime number, it would have been required that 66 has only two divisors, i.e., itself and 1.

### Is 66 a deficient number?

No, 66 is not a deficient number: to be deficient, 66 should have been such that 66 is larger than the sum of its proper divisors, i.e., the divisors of 66 without 66 itself (that is 1 + 2 + 3 + 6 + 11 + 22 + 33 = 78).

In fact, 66 is an abundant number; 66 is strictly smaller than the sum of its proper divisors (that is 1 + 2 + 3 + 6 + 11 + 22 + 33 = 78). The smallest abundant number is 12.