256700555809 has 2 divisors, whose sum is σ = 256700555810. Its totient is φ = 256700555808.

The previous prime is 256700555779. The next prime is 256700555843. The reversal of 256700555809 is 908555007652.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 233496736225 + 23203819584 = 483215^2 + 152328^2 .

It is a cyclic number.

It is not a de Polignac number, because 256700555809 - 2⁷ = 256700555681 is a prime.

It is not a weakly prime, because it can be changed into another prime (256700555869) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128350277904 + 128350277905.

It is an arithmetic number, because the mean of its divisors is an integer number (128350277905).

Almost surely, 2^256700555809 is an apocalyptic number.

It is an amenable number.

256700555809 is a deficient number, since it is larger than the sum of its proper divisors (1).

256700555809 is an equidigital number, since it uses as much as digits as its factorization.

256700555809 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3780000, while the sum is 52.

The spelling of 256700555809 in words is "two hundred fifty-six billion, seven hundred million, five hundred fifty-five thousand, eight hundred nine".