256621600554555 has 64 divisors (see below), whose sum is σ = 441499320078336. Its totient is φ = 126818522880000.

The previous prime is 256621600554503. The next prime is 256621600554563. The reversal of 256621600554555 is 555455006126652.

It is not a de Polignac number, because 256621600554555 - 2¹⁰ = 256621600553531 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 256621600554495 and 256621600554504.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (31) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 2581710 + ... + 22801500.

It is an arithmetic number, because the mean of its divisors is an integer number (6898426876224).

Almost surely, 2^{256621600554555} is an apocalyptic number.

256621600554555 is a deficient number, since it is larger than the sum of its proper divisors (184877719523781).

256621600554555 is a wasteful number, since it uses less digits than its factorization.

256621600554555 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20220588.

The product of its (nonzero) digits is 54000000, while the sum is 57.

The spelling of 256621600554555 in words is "two hundred fifty-six trillion, six hundred twenty-one billion, six hundred million, five hundred fifty-four thousand, five hundred fifty-five".