256323517 has 2 divisors, whose sum is σ = 256323518. Its totient is φ = 256323516.

The previous prime is 256323499. The next prime is 256323563. The reversal of 256323517 is 715323652.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 250462276 + 5861241 = 15826^2 + 2421^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-256323517 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (256323577) 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, 128161758 + 128161759.

It is an arithmetic number, because the mean of its divisors is an integer number (128161759).

Almost surely, 2^256323517 is an apocalyptic number.

It is an amenable number.

256323517 is a deficient number, since it is larger than the sum of its proper divisors (1).

256323517 is an equidigital number, since it uses as much as digits as its factorization.

256323517 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 37800, while the sum is 34.

The square root of 256323517 is about 16010.1067141978. The cubic root of 256323517 is about 635.2277827906.

The spelling of 256323517 in words is "two hundred fifty-six million, three hundred twenty-three thousand, five hundred seventeen".