256644660518712 has 24 divisors (see below), whose sum is σ = 695079288905040. Its totient is φ = 85548220172880.

The previous prime is 256644660518581. The next prime is 256644660518713. The reversal of 256644660518712 is 217815066446652.

256644660518712 is a `hidden beast` number, since 2 + 5 + 6 + 6 + 4 + 4 + 6 + 605 + 1 + 8 + 7 + 12 = 666.

It is a tau number, because it is divible by the number of its divisors (24).

It is a self number, because there is not a number n which added to its sum of digits gives 256644660518712.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256644660518713) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1782254586864 + ... + 1782254587007.

It is an arithmetic number, because the mean of its divisors is an integer number (28961637037710).

Almost surely, 2^{256644660518712} is an apocalyptic number.

It is an amenable number.

256644660518712 is an abundant number, since it is smaller than the sum of its proper divisors (438434628386328).

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

256644660518712 is a wasteful number, since it uses less digits than its factorization.

256644660518712 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3564509173883 (or 3564509173876 counting only the distinct ones).

The product of its (nonzero) digits is 116121600, while the sum is 63.

The spelling of 256644660518712 in words is "two hundred fifty-six trillion, six hundred forty-four billion, six hundred sixty million, five hundred eighteen thousand, seven hundred twelve".