256631677046791 has 2 divisors, whose sum is σ = 256631677046792. Its totient is φ = 256631677046790.

The previous prime is 256631677046683. The next prime is 256631677046837. The reversal of 256631677046791 is 197640776136652.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 256631677046791 - 2¹⁵ = 256631677014023 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 256631677046791.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (256631377046791) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128315838523395 + 128315838523396.

It is an arithmetic number, because the mean of its divisors is an integer number (128315838523396).

Almost surely, 2^{256631677046791} is an apocalyptic number.

256631677046791 is a deficient number, since it is larger than the sum of its proper divisors (1).

256631677046791 is an equidigital number, since it uses as much as digits as its factorization.

256631677046791 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 480090240, while the sum is 70.

The spelling of 256631677046791 in words is "two hundred fifty-six trillion, six hundred thirty-one billion, six hundred seventy-seven million, forty-six thousand, seven hundred ninety-one".