666913 has 12 divisors (see below), whose sum is σ = 756028. Its totient is φ = 584640.

The previous prime is 666901. The next prime is 666929. The reversal of 666913 is 319666.

It can be written as a sum of positive squares in 6 ways, for example, as 138384 + 528529 = 372^2 + 727^2 .

It is a de Polignac number, because none of the positive numbers 2^k-666913 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666983) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 10903 + ... + 10963.

2⁶⁶⁶⁹¹³ is an apocalyptic number.

It is an amenable number.

666913 is a deficient number, since it is larger than the sum of its proper divisors (89115).

666913 is a wasteful number, since it uses less digits than its factorization.

666913 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 132 (or 103 counting only the distinct ones).

The product of its digits is 5832, while the sum is 31.

The square root of 666913 is about 816.6474147391. The cubic root of 666913 is about 87.3688047481.

The spelling of 666913 in words is "six hundred sixty-six thousand, nine hundred thirteen".