256845 has 8 divisors (see below), whose sum is σ = 410976. Its totient is φ = 136976.

The previous prime is 256831. The next prime is 256873. The reversal of 256845 is 548652.

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 256845 - 2⁵ = 256813 is a prime.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8547 + ... + 8576.

It is an arithmetic number, because the mean of its divisors is an integer number (51372).

2²⁵⁶⁸⁴⁵ is an apocalyptic number.

It is an amenable number.

256845 is a deficient number, since it is larger than the sum of its proper divisors (154131).

256845 is a wasteful number, since it uses less digits than its factorization.

256845 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17131.

The product of its digits is 9600, while the sum is 30.

The square root of 256845 is about 506.7987766363. The cubic root of 256845 is about 63.5658275345.

The spelling of 256845 in words is "two hundred fifty-six thousand, eight hundred forty-five".