256621061364587 has 2 divisors, whose sum is σ = 256621061364588. Its totient is φ = 256621061364586.

The previous prime is 256621061364523. The next prime is 256621061364589. The reversal of 256621061364587 is 785463160126652.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 256621061364587 - 2⁶ = 256621061364523 is a prime.

Together with 256621061364589, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (256621061364589) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128310530682293 + 128310530682294.

It is an arithmetic number, because the mean of its divisors is an integer number (128310530682294).

Almost surely, 2^{256621061364587} is an apocalyptic number.

256621061364587 is a deficient number, since it is larger than the sum of its proper divisors (1).

256621061364587 is an equidigital number, since it uses as much as digits as its factorization.

256621061364587 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 87091200, while the sum is 62.

The spelling of 256621061364587 in words is "two hundred fifty-six trillion, six hundred twenty-one billion, sixty-one million, three hundred sixty-four thousand, five hundred eighty-seven".