256445 has 16 divisors (see below), whose sum is σ = 373248. Its totient is φ = 165120.

The previous prime is 256441. The next prime is 256469. The reversal of 256445 is 544652.

256445 = 68² + 69² + ... + 102².

It is not a de Polignac number, because 256445 - 2² = 256441 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256441) 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 15 ways as a sum of consecutive naturals, for example, 380 + ... + 810.

It is an arithmetic number, because the mean of its divisors is an integer number (23328).

2²⁵⁶⁴⁴⁵ is an apocalyptic number.

It is an amenable number.

256445 is a deficient number, since it is larger than the sum of its proper divisors (116803).

256445 is a wasteful number, since it uses less digits than its factorization.

256445 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 460.

The product of its digits is 4800, while the sum is 26.

The square root of 256445 is about 506.4039889258. The cubic root of 256445 is about 63.5328121079.

The spelling of 256445 in words is "two hundred fifty-six thousand, four hundred forty-five".