256840998023 has 2 divisors, whose sum is σ = 256840998024. Its totient is φ = 256840998022.

The previous prime is 256840997993. The next prime is 256840998083. The reversal of 256840998023 is 320899048652.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 256840998023 - 2¹⁰ = 256840996999 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 256840998023.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (256840998083) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128420499011 + 128420499012.

It is an arithmetic number, because the mean of its divisors is an integer number (128420499012).

Almost surely, 2^256840998023 is an apocalyptic number.

256840998023 is a deficient number, since it is larger than the sum of its proper divisors (1).

256840998023 is an equidigital number, since it uses as much as digits as its factorization.

256840998023 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 7464960, while the sum is 56.

The spelling of 256840998023 in words is "two hundred fifty-six billion, eight hundred forty million, nine hundred ninety-eight thousand, twenty-three".