666904 has 16 divisors (see below), whose sum is σ = 1429200. Its totient is φ = 285792.

The previous prime is 666901. The next prime is 666929. The reversal of 666904 is 409666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666901) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5899 + ... + 6010.

It is an arithmetic number, because the mean of its divisors is an integer number (89325).

2⁶⁶⁶⁹⁰⁴ is an apocalyptic number.

It is an amenable number.

666904 is an abundant number, since it is smaller than the sum of its proper divisors (762296).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

666904 is a wasteful number, since it uses less digits than its factorization.

666904 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11922 (or 11918 counting only the distinct ones).

The product of its (nonzero) digits is 7776, while the sum is 31.

The square root of 666904 is about 816.6419043865. The cubic root of 666904 is about 87.3684117319.

The spelling of 666904 in words is "six hundred sixty-six thousand, nine hundred four".