256477717 has 2 divisors, whose sum is σ = 256477718. Its totient is φ = 256477716.

The previous prime is 256477709. The next prime is 256477777. The reversal of 256477717 is 717774652.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 243796996 + 12680721 = 15614^2 + 3561^2 .

It is a cyclic number.

It is not a de Polignac number, because 256477717 - 2³ = 256477709 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (256477777) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128238858 + 128238859.

It is an arithmetic number, because the mean of its divisors is an integer number (128238859).

Almost surely, 2^256477717 is an apocalyptic number.

It is an amenable number.

256477717 is a deficient number, since it is larger than the sum of its proper divisors (1).

256477717 is an equidigital number, since it uses as much as digits as its factorization.

256477717 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 576240, while the sum is 46.

The square root of 256477717 is about 16014.9216982163. The cubic root of 256477717 is about 635.3551381080.

The spelling of 256477717 in words is "two hundred fifty-six million, four hundred seventy-seven thousand, seven hundred seventeen".