256696598591 has 4 divisors (see below), whose sum is σ = 257643818784. Its totient is φ = 255749378400.

The previous prime is 256696598573. The next prime is 256696598629. The reversal of 256696598591 is 195895696652.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-256696598591 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256696598551) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 473609690 + ... + 473610231.

It is an arithmetic number, because the mean of its divisors is an integer number (64410954696).

Almost surely, 2^256696598591 is an apocalyptic number.

256696598591 is a deficient number, since it is larger than the sum of its proper divisors (947220193).

256696598591 is an equidigital number, since it uses as much as digits as its factorization.

256696598591 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 947220192.

The product of its digits is 314928000, while the sum is 71.

The spelling of 256696598591 in words is "two hundred fifty-six billion, six hundred ninety-six million, five hundred ninety-eight thousand, five hundred ninety-one".