256249767577 has 2 divisors, whose sum is σ = 256249767578. Its totient is φ = 256249767576.

The previous prime is 256249767547. The next prime is 256249767581. The reversal of 256249767577 is 775767942652.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 209083049536 + 47166718041 = 457256^2 + 217179^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-256249767577 is a prime.

It is not a weakly prime, because it can be changed into another prime (256249767547) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128124883788 + 128124883789.

It is an arithmetic number, because the mean of its divisors is an integer number (128124883789).

Almost surely, 2^256249767577 is an apocalyptic number.

It is an amenable number.

256249767577 is a deficient number, since it is larger than the sum of its proper divisors (1).

256249767577 is an equidigital number, since it uses as much as digits as its factorization.

256249767577 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 311169600, while the sum is 67.

The spelling of 256249767577 in words is "two hundred fifty-six billion, two hundred forty-nine million, seven hundred sixty-seven thousand, five hundred seventy-seven".