256867 has 4 divisors (see below), whose sum is σ = 276640. Its totient is φ = 237096.

The previous prime is 256831. The next prime is 256873. The reversal of 256867 is 768652.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-256867 is a prime.

It is a nialpdrome in base 8.

It is not an unprimeable number, because it can be changed into a prime (256877) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9867 + ... + 9892.

It is an arithmetic number, because the mean of its divisors is an integer number (69160).

2²⁵⁶⁸⁶⁷ is an apocalyptic number.

256867 is a deficient number, since it is larger than the sum of its proper divisors (19773).

256867 is a wasteful number, since it uses less digits than its factorization.

256867 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19772.

The product of its digits is 20160, while the sum is 34.

The square root of 256867 is about 506.8204810384. The cubic root of 256867 is about 63.5676423882.

The spelling of 256867 in words is "two hundred fifty-six thousand, eight hundred sixty-seven".