666556684 has 12 divisors (see below), whose sum is σ = 1166679304. Its totient is φ = 333219744.

The previous prime is 666556661. The next prime is 666556711. The reversal of 666556684 is 486655666.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 20104 + ... + 41680.

Almost surely, 2^666556684 is an apocalyptic number.

It is an amenable number.

666556684 is a deficient number, since it is larger than the sum of its proper divisors (500122620).

666556684 is a wasteful number, since it uses less digits than its factorization.

666556684 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29304 (or 29302 counting only the distinct ones).

The product of its digits is 6220800, while the sum is 52.

The square root of 666556684 is about 25817.7590816864. The cubic root of 666556684 is about 873.5324227398.

The spelling of 666556684 in words is "six hundred sixty-six million, five hundred fifty-six thousand, six hundred eighty-four".