256873541665 has 48 divisors (see below), whose sum is σ = 348495713280. Its totient is φ = 181339741440.

The previous prime is 256873541629. The next prime is 256873541669. The reversal of 256873541665 is 566145378652.

It is a happy number.

It is not a de Polignac number, because 256873541665 - 2¹¹ = 256873539617 is a prime.

It is not an unprimeable number, because it can be changed into a prime (256873541669) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 52841335 + ... + 52846195.

It is an arithmetic number, because the mean of its divisors is an integer number (7260327360).

Almost surely, 2^256873541665 is an apocalyptic number.

It is an amenable number.

256873541665 is a deficient number, since it is larger than the sum of its proper divisors (91622171615).

256873541665 is a wasteful number, since it uses less digits than its factorization.

256873541665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7634 (or 7621 counting only the distinct ones).

The product of its digits is 36288000, while the sum is 58.

The spelling of 256873541665 in words is "two hundred fifty-six billion, eight hundred seventy-three million, five hundred forty-one thousand, six hundred sixty-five".