256164257 has 2 divisors, whose sum is σ = 256164258. Its totient is φ = 256164256.

The previous prime is 256164239. The next prime is 256164277. The reversal of 256164257 is 752461652.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 234671761 + 21492496 = 15319^2 + 4636^2 .

It is a cyclic number.

It is not a de Polignac number, because 256164257 - 2⁸ = 256164001 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 256164257.

It is not a weakly prime, because it can be changed into another prime (256164217) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128082128 + 128082129.

It is an arithmetic number, because the mean of its divisors is an integer number (128082129).

Almost surely, 2^256164257 is an apocalyptic number.

It is an amenable number.

256164257 is a deficient number, since it is larger than the sum of its proper divisors (1).

256164257 is an equidigital number, since it uses as much as digits as its factorization.

256164257 is an evil number, because the sum of its binary digits is even.

The product of its digits is 100800, while the sum is 38.

The square root of 256164257 is about 16005.1322081387. The cubic root of 256164257 is about 635.0961947394.

The spelling of 256164257 in words is "two hundred fifty-six million, one hundred sixty-four thousand, two hundred fifty-seven".