256566677 has 2 divisors, whose sum is σ = 256566678. Its totient is φ = 256566676.

The previous prime is 256566659. The next prime is 256566733. The reversal of 256566677 is 776665652.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 255808036 + 758641 = 15994^2 + 871^2 .

It is a cyclic number.

It is not a de Polignac number, because 256566677 - 2⁸ = 256566421 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (256566637) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128283338 + 128283339.

It is an arithmetic number, because the mean of its divisors is an integer number (128283339).

Almost surely, 2^256566677 is an apocalyptic number.

It is an amenable number.

256566677 is a deficient number, since it is larger than the sum of its proper divisors (1).

256566677 is an equidigital number, since it uses as much as digits as its factorization.

256566677 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3175200, while the sum is 50.

The square root of 256566677 is about 16017.6988671906. The cubic root of 256566677 is about 635.4285878410.

The spelling of 256566677 in words is "two hundred fifty-six million, five hundred sixty-six thousand, six hundred seventy-seven".