664610525856 has 72 divisors (see below), whose sum is σ = 1922019896160. Its totient is φ = 217781974656.

The previous prime is 664610525849. The next prime is 664610525857. The reversal of 664610525856 is 658525016466.

664610525856 is a `hidden beast` number, since 6 + 6 + 4 + 6 + 1 + 0 + 52 + 585 + 6 = 666.

It is a tau number, because it is divible by the number of its divisors (72).

It is not an unprimeable number, because it can be changed into a prime (664610525857) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 19539580 + ... + 19573563.

It is an arithmetic number, because the mean of its divisors is an integer number (26694720780).

Almost surely, 2^664610525856 is an apocalyptic number.

It is an amenable number.

664610525856 is an abundant number, since it is smaller than the sum of its proper divisors (1257409370304).

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

664610525856 is a wasteful number, since it uses less digits than its factorization.

664610525856 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39113218 (or 39113207 counting only the distinct ones).

The product of its (nonzero) digits is 10368000, while the sum is 54.

The spelling of 664610525856 in words is "six hundred sixty-four billion, six hundred ten million, five hundred twenty-five thousand, eight hundred fifty-six".