664868660 has 24 divisors (see below), whose sum is σ = 1396743936. Its totient is φ = 265848480.

The previous prime is 664868599. The next prime is 664868681. The reversal of 664868660 is 66868466.

It is a junction number, because it is equal to n+sod(n) for n = 664868599 and 664868608.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 74645 + ... + 83075.

It is an arithmetic number, because the mean of its divisors is an integer number (58197664).

Almost surely, 2^664868660 is an apocalyptic number.

It is an amenable number.

664868660 is an abundant number, since it is smaller than the sum of its proper divisors (731875276).

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

664868660 is a wasteful number, since it uses less digits than its factorization.

664868660 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12383 (or 12381 counting only the distinct ones).

The product of its (nonzero) digits is 1990656, while the sum is 50.

The square root of 664868660 is about 25785.0472173312. The cubic root of 664868660 is about 872.7944058929.

The spelling of 664868660 in words is "six hundred sixty-four million, eight hundred sixty-eight thousand, six hundred sixty".