256742712756717 has 32 divisors (see below), whose sum is σ = 399038862879360. Its totient is φ = 145105040977920.

The previous prime is 256742712756703. The next prime is 256742712756737. The reversal of 256742712756717 is 717657217247652.

It is a happy number.

It is not a de Polignac number, because 256742712756717 - 2¹⁸ = 256742712494573 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256742712756737) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2099259468 + ... + 2099381765.

It is an arithmetic number, because the mean of its divisors is an integer number (12469964464980).

Almost surely, 2^{256742712756717} is an apocalyptic number.

It is an amenable number.

256742712756717 is a deficient number, since it is larger than the sum of its proper divisors (142296150122643).

256742712756717 is a wasteful number, since it uses less digits than its factorization.

256742712756717 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4198641373.

The product of its digits is 484041600, while the sum is 69.

The spelling of 256742712756717 in words is "two hundred fifty-six trillion, seven hundred forty-two billion, seven hundred twelve million, seven hundred fifty-six thousand, seven hundred seventeen".