256621526602559 has 2 divisors, whose sum is σ = 256621526602560. Its totient is φ = 256621526602558.

The previous prime is 256621526602471. The next prime is 256621526602607. The reversal of 256621526602559 is 955206625126652.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 256621526602559 - 2¹⁶ = 256621526537023 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (256621526602759) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128310763301279 + 128310763301280.

It is an arithmetic number, because the mean of its divisors is an integer number (128310763301280).

Almost surely, 2^{256621526602559} is an apocalyptic number.

256621526602559 is a deficient number, since it is larger than the sum of its proper divisors (1).

256621526602559 is an equidigital number, since it uses as much as digits as its factorization.

256621526602559 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 116640000, while the sum is 62.

The spelling of 256621526602559 in words is "two hundred fifty-six trillion, six hundred twenty-one billion, five hundred twenty-six million, six hundred two thousand, five hundred fifty-nine".