256809101911 has 2 divisors, whose sum is σ = 256809101912. Its totient is φ = 256809101910.

The previous prime is 256809101891. The next prime is 256809101933. The reversal of 256809101911 is 119101908652.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 256809101911 - 2⁹ = 256809101399 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (256809101611) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128404550955 + 128404550956.

It is an arithmetic number, because the mean of its divisors is an integer number (128404550956).

Almost surely, 2^256809101911 is an apocalyptic number.

256809101911 is a deficient number, since it is larger than the sum of its proper divisors (1).

256809101911 is an equidigital number, since it uses as much as digits as its factorization.

256809101911 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 38880, while the sum is 43.

The spelling of 256809101911 in words is "two hundred fifty-six billion, eight hundred nine million, one hundred one thousand, nine hundred eleven".