256331680513 has 2 divisors, whose sum is σ = 256331680514. Its totient is φ = 256331680512.

The previous prime is 256331680483. The next prime is 256331680541. The reversal of 256331680513 is 315086133652.

It is a happy number.

256331680513 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 152487907009 + 103843773504 = 390497^2 + 322248^2 .

It is a cyclic number.

It is not a de Polignac number, because 256331680513 - 2⁵ = 256331680481 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 256331680513.

It is not a weakly prime, because it can be changed into another prime (256331650513) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128165840256 + 128165840257.

It is an arithmetic number, because the mean of its divisors is an integer number (128165840257).

Almost surely, 2^256331680513 is an apocalyptic number.

It is an amenable number.

256331680513 is a deficient number, since it is larger than the sum of its proper divisors (1).

256331680513 is an equidigital number, since it uses as much as digits as its factorization.

256331680513 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 388800, while the sum is 43.

The spelling of 256331680513 in words is "two hundred fifty-six billion, three hundred thirty-one million, six hundred eighty thousand, five hundred thirteen".