256863 has 4 divisors (see below), whose sum is σ = 342488. Its totient is φ = 171240.

The previous prime is 256831. The next prime is 256873. The reversal of 256863 is 368652.

256863 is nontrivially palindromic in base 2.

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

It is not a de Polignac number, because 256863 - 2⁵ = 256831 is a prime.

It is an Ulam number.

It is a D-number.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 256863.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256813) 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, 42808 + ... + 42813.

It is an arithmetic number, because the mean of its divisors is an integer number (85622).

2²⁵⁶⁸⁶³ is an apocalyptic number.

256863 is a deficient number, since it is larger than the sum of its proper divisors (85625).

256863 is an equidigital number, since it uses as much as digits as its factorization.

256863 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 85624.

The product of its digits is 8640, while the sum is 30.

The square root of 256863 is about 506.8165348526. The cubic root of 256863 is about 63.5673124225.

It can be divided in two parts, 2 and 56863, that added together give a palindrome (56865).

The spelling of 256863 in words is "two hundred fifty-six thousand, eight hundred sixty-three".