256644767925 has 480 divisors, whose sum is σ = 611851116800. Its totient is φ = 105619852800.

The previous prime is 256644767921. The next prime is 256644767927. The reversal of 256644767925 is 529767446652.

256644767925 is a `hidden beast` number, since 2 + 566 + 4 + 4 + 7 + 67 + 9 + 2 + 5 = 666.

It is not a de Polignac number, because 256644767925 - 2² = 256644767921 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256644767921) by changing a digit.

It is a polite number, since it can be written in 479 ways as a sum of consecutive naturals, for example, 388267095 + ... + 388267755.

Almost surely, 2^256644767925 is an apocalyptic number.

256644767925 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

256644767925 is an abundant number, since it is smaller than the sum of its proper divisors (355206348875).

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

256644767925 is a wasteful number, since it uses less digits than its factorization.

256644767925 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 760 (or 732 counting only the distinct ones).

The product of its digits is 152409600, while the sum is 63.

The spelling of 256644767925 in words is "two hundred fifty-six billion, six hundred forty-four million, seven hundred sixty-seven thousand, nine hundred twenty-five".