256823 has 8 divisors (see below), whose sum is σ = 309120. Its totient is φ = 208440.

The previous prime is 256813. The next prime is 256831. The reversal of 256823 is 328652.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 256823 - 2⁸ = 256567 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 256792 and 256801.

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

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 833 + ... + 1098.

It is an arithmetic number, because the mean of its divisors is an integer number (38640).

2²⁵⁶⁸²³ is an apocalyptic number.

256823 is a deficient number, since it is larger than the sum of its proper divisors (52297).

256823 is a wasteful number, since it uses less digits than its factorization.

256823 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1957.

The product of its digits is 2880, while the sum is 26.

The square root of 256823 is about 506.7770713045. Note that the first 3 decimals coincide. The cubic root of 256823 is about 63.5640125772.

The spelling of 256823 in words is "two hundred fifty-six thousand, eight hundred twenty-three".