256842577 has 2 divisors, whose sum is σ = 256842578. Its totient is φ = 256842576.

The previous prime is 256842563. The next prime is 256842581. The reversal of 256842577 is 775248652.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 190191681 + 66650896 = 13791^2 + 8164^2 .

It is a cyclic number.

It is not a de Polignac number, because 256842577 - 2¹⁵ = 256809809 is a prime.

It is not a weakly prime, because it can be changed into another prime (256842877) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128421288 + 128421289.

It is an arithmetic number, because the mean of its divisors is an integer number (128421289).

Almost surely, 2^256842577 is an apocalyptic number.

It is an amenable number.

256842577 is a deficient number, since it is larger than the sum of its proper divisors (1).

256842577 is an equidigital number, since it uses as much as digits as its factorization.

256842577 is an evil number, because the sum of its binary digits is even.

The product of its digits is 940800, while the sum is 46.

The square root of 256842577 is about 16026.3089013035. The cubic root of 256842577 is about 635.6562764677.

The spelling of 256842577 in words is "two hundred fifty-six million, eight hundred forty-two thousand, five hundred seventy-seven".