256762807817 has 2 divisors, whose sum is σ = 256762807818. Its totient is φ = 256762807816.

The previous prime is 256762807783. The next prime is 256762807837. The reversal of 256762807817 is 718708267652.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 141800446096 + 114962361721 = 376564^2 + 339061^2 .

It is a cyclic number.

It is not a de Polignac number, because 256762807817 - 2¹⁰ = 256762806793 is a prime.

It is not a weakly prime, because it can be changed into another prime (256762807837) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128381403908 + 128381403909.

It is an arithmetic number, because the mean of its divisors is an integer number (128381403909).

Almost surely, 2^256762807817 is an apocalyptic number.

It is an amenable number.

256762807817 is a deficient number, since it is larger than the sum of its proper divisors (1).

256762807817 is an equidigital number, since it uses as much as digits as its factorization.

256762807817 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 15805440, while the sum is 59.

The spelling of 256762807817 in words is "two hundred fifty-six billion, seven hundred sixty-two million, eight hundred seven thousand, eight hundred seventeen".