256897871 has 2 divisors, whose sum is σ = 256897872. Its totient is φ = 256897870.

The previous prime is 256897847. The next prime is 256897873. The reversal of 256897871 is 178798652.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 256897871 - 2¹⁰ = 256896847 is a prime.

It is a super-2 number, since 2×256897871² = 131993032248665282, which contains 22 as substring.

Together with 256897873, 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 (256897873) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128448935 + 128448936.

It is an arithmetic number, because the mean of its divisors is an integer number (128448936).

Almost surely, 2^256897871 is an apocalyptic number.

256897871 is a deficient number, since it is larger than the sum of its proper divisors (1).

256897871 is an equidigital number, since it uses as much as digits as its factorization.

256897871 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1693440, while the sum is 53.

The square root of 256897871 is about 16028.0339093727. The cubic root of 256897871 is about 635.7018886564.

The spelling of 256897871 in words is "two hundred fifty-six million, eight hundred ninety-seven thousand, eight hundred seventy-one".