256929 has 4 divisors (see below), whose sum is σ = 342576. Its totient is φ = 171284.

The previous prime is 256903. The next prime is 256931. The reversal of 256929 is 929652.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 256929 - 2⁷ = 256801 is a prime.

It is a super-2 number, since 2×256929² = 132025022082, which contains 22 as substring.

It is an Ulam number.

It is a D-number.

It is an alternating number because its digits alternate between even and odd.

It is a self number, because there is not a number n which added to its sum of digits gives 256929.

It is not an unprimeable number, because it can be changed into a prime (256939) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 42819 + ... + 42824.

It is an arithmetic number, because the mean of its divisors is an integer number (85644).

2²⁵⁶⁹²⁹ is an apocalyptic number.

It is an amenable number.

256929 is a deficient number, since it is larger than the sum of its proper divisors (85647).

256929 is an equidigital number, since it uses as much as digits as its factorization.

256929 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 85646.

The product of its digits is 9720, while the sum is 33.

The square root of 256929 is about 506.8816429898. The cubic root of 256929 is about 63.5727564184.

The spelling of 256929 in words is "two hundred fifty-six thousand, nine hundred twenty-nine".