256271591 has 2 divisors, whose sum is σ = 256271592. Its totient is φ = 256271590.

The previous prime is 256271581. The next prime is 256271593. The reversal of 256271591 is 195172652.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-256271591 is a prime.

Together with 256271593, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (256271593) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128135795 + 128135796.

It is an arithmetic number, because the mean of its divisors is an integer number (128135796).

Almost surely, 2^256271591 is an apocalyptic number.

256271591 is a deficient number, since it is larger than the sum of its proper divisors (1).

256271591 is an equidigital number, since it uses as much as digits as its factorization.

256271591 is an evil number, because the sum of its binary digits is even.

The product of its digits is 37800, while the sum is 38.

The square root of 256271591 is about 16008.4849689157. The cubic root of 256271591 is about 635.1848850939.

The spelling of 256271591 in words is "two hundred fifty-six million, two hundred seventy-one thousand, five hundred ninety-one".