665655664 has 20 divisors (see below), whose sum is σ = 1321165440. Its totient is φ = 324709760.

The previous prime is 665655643. The next prime is 665655701. The reversal of 665655664 is 466556566.

665655664 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent 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, 506704 + ... + 508015.

It is an arithmetic number, because the mean of its divisors is an integer number (66058272).

Almost surely, 2^665655664 is an apocalyptic number.

It is an amenable number.

665655664 is a deficient number, since it is larger than the sum of its proper divisors (655509776).

665655664 is a wasteful number, since it uses less digits than its factorization.

665655664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1014768 (or 1014762 counting only the distinct ones).

The product of its digits is 3888000, while the sum is 49.

The square root of 665655664 is about 25800.3035641056. The cubic root of 665655664 is about 873.1386452309.

The spelling of 665655664 in words is "six hundred sixty-five million, six hundred fifty-five thousand, six hundred sixty-four".