256465 has 8 divisors (see below), whose sum is σ = 335808. Its totient is φ = 186480.

The previous prime is 256441. The next prime is 256469. The reversal of 256465 is 564652.

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

It is not a de Polignac number, because 256465 - 2⁷ = 256337 is a prime.

It is not an unprimeable number, because it can be changed into a prime (256469) 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 7 ways as a sum of consecutive naturals, for example, 2277 + ... + 2386.

It is an arithmetic number, because the mean of its divisors is an integer number (41976).

2²⁵⁶⁴⁶⁵ is an apocalyptic number.

It is an amenable number.

256465 is a deficient number, since it is larger than the sum of its proper divisors (79343).

256465 is a wasteful number, since it uses less digits than its factorization.

256465 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4679.

The product of its digits is 7200, while the sum is 28.

The square root of 256465 is about 506.4237356207. The cubic root of 256465 is about 63.5344636942.

It can be divided in two parts, 25646 and 5, that added together give a triangular number (25651 = T₂₂₆).

The spelling of 256465 in words is "two hundred fifty-six thousand, four hundred sixty-five".