256871 has 4 divisors (see below), whose sum is σ = 261144. Its totient is φ = 252600.

The previous prime is 256831. The next prime is 256873. The reversal of 256871 is 178652.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 256871 - 2¹⁰ = 255847 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256873) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2045 + ... + 2166.

It is an arithmetic number, because the mean of its divisors is an integer number (65286).

2²⁵⁶⁸⁷¹ is an apocalyptic number.

256871 is a deficient number, since it is larger than the sum of its proper divisors (4273).

256871 is an equidigital number, since it uses as much as digits as its factorization.

256871 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4272.

The product of its digits is 3360, while the sum is 29.

The square root of 256871 is about 506.8244271935. The cubic root of 256871 is about 63.5679723504.

The spelling of 256871 in words is "two hundred fifty-six thousand, eight hundred seventy-one".