256621604723365 has 16 divisors (see below), whose sum is σ = 352204618844160. Its totient is φ = 175835891341440.

The previous prime is 256621604723359. The next prime is 256621604723441. The reversal of 256621604723365 is 563327406126652.

It is not a de Polignac number, because 256621604723365 - 2²⁷ = 256621470505637 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2775141445 + ... + 2775233914.

It is an arithmetic number, because the mean of its divisors is an integer number (22012788677760).

Almost surely, 2^{256621604723365} is an apocalyptic number.

It is an amenable number.

256621604723365 is a deficient number, since it is larger than the sum of its proper divisors (95583014120795).

256621604723365 is a wasteful number, since it uses less digits than its factorization.

256621604723365 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5550376692.

The product of its (nonzero) digits is 65318400, while the sum is 58.

The spelling of 256621604723365 in words is "two hundred fifty-six trillion, six hundred twenty-one billion, six hundred four million, seven hundred twenty-three thousand, three hundred sixty-five".