256385671 has 2 divisors, whose sum is σ = 256385672. Its totient is φ = 256385670.

The previous prime is 256385599. The next prime is 256385719. The reversal of 256385671 is 176583652.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 256385671 - 2¹⁵ = 256352903 is a prime.

It is a super-2 number, since 2×256385671² = 131467224588240482, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (256385971) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128192835 + 128192836.

It is an arithmetic number, because the mean of its divisors is an integer number (128192836).

Almost surely, 2^256385671 is an apocalyptic number.

256385671 is a deficient number, since it is larger than the sum of its proper divisors (1).

256385671 is an equidigital number, since it uses as much as digits as its factorization.

256385671 is an evil number, because the sum of its binary digits is even.

The product of its digits is 302400, while the sum is 43.

The square root of 256385671 is about 16012.0476829168. The cubic root of 256385671 is about 635.2791225419.

The spelling of 256385671 in words is "two hundred fifty-six million, three hundred eighty-five thousand, six hundred seventy-one".