665884656 has 60 divisors (see below), whose sum is σ = 1868050080. Its totient is φ = 221425920.

The previous prime is 665884613. The next prime is 665884693. The reversal of 665884656 is 656488566.

It is a happy number.

665884656 is a `hidden beast` number, since 6 + 6 + 588 + 4 + 6 + 56 = 666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 56700 + ... + 67428.

It is an arithmetic number, because the mean of its divisors is an integer number (31134168).

Almost surely, 2^665884656 is an apocalyptic number.

It is an amenable number.

665884656 is an abundant number, since it is smaller than the sum of its proper divisors (1202165424).

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

665884656 is a wasteful number, since it uses less digits than its factorization.

665884656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11174 (or 11165 counting only the distinct ones).

The product of its digits is 8294400, while the sum is 54.

The square root of 665884656 is about 25804.7409597539. The cubic root of 665884656 is about 873.2387564709.

The spelling of 665884656 in words is "six hundred sixty-five million, eight hundred eighty-four thousand, six hundred fifty-six".