256654945665 has 192 divisors, whose sum is σ = 502831929600. Its totient is φ = 120339136512.

The previous prime is 256654945639. The next prime is 256654945669. The reversal of 256654945665 is 566549456652.

256654945665 is a `hidden beast` number, since 2 + 5 + 6 + 65 + 4 + 9 + 4 + 566 + 5 = 666.

It is not a de Polignac number, because 256654945665 - 2¹⁵ = 256654912897 is a prime.

It is a super-2 number, since 2×256654945665² (a number of 24 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (256654945669) by changing a digit.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 504233431 + ... + 504233939.

It is an arithmetic number, because the mean of its divisors is an integer number (2618916300).

Almost surely, 2^256654945665 is an apocalyptic number.

It is an amenable number.

256654945665 is a deficient number, since it is larger than the sum of its proper divisors (246176983935).

256654945665 is a wasteful number, since it uses less digits than its factorization.

256654945665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 976 (or 973 counting only the distinct ones).

The product of its digits is 233280000, while the sum is 63.

The spelling of 256654945665 in words is "two hundred fifty-six billion, six hundred fifty-four million, nine hundred forty-five thousand, six hundred sixty-five".