256666188988 has 24 divisors (see below), whose sum is σ = 490266854784. Its totient is φ = 116602695600.

The previous prime is 256666188971. The next prime is 256666189019. The reversal of 256666188988 is 889881666652.

It is a self number, because there is not a number n which added to its sum of digits gives 256666188988.

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, 1512370 + ... + 1673497.

It is an arithmetic number, because the mean of its divisors is an integer number (20427785616).

Almost surely, 2^256666188988 is an apocalyptic number.

It is an amenable number.

256666188988 is a deficient number, since it is larger than the sum of its proper divisors (233600665796).

256666188988 is a wasteful number, since it uses less digits than its factorization.

256666188988 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3187713 (or 3187711 counting only the distinct ones).

The product of its digits is 477757440, while the sum is 73.

The spelling of 256666188988 in words is "two hundred fifty-six billion, six hundred sixty-six million, one hundred eighty-eight thousand, nine hundred eighty-eight".