256564 has 48 divisors (see below), whose sum is σ = 604800. Its totient is φ = 94080.

The previous prime is 256561. The next prime is 256567. The reversal of 256564 is 465652.

It is an interprime number because it is at equal distance from previous prime (256561) and next prime (256567).

It is a Harshad number since it is a multiple of its sum of digits (28).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256561) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 15084 + ... + 15100.

It is an arithmetic number, because the mean of its divisors is an integer number (12600).

2²⁵⁶⁵⁶⁴ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 256564, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (302400).

256564 is an abundant number, since it is smaller than the sum of its proper divisors (348236).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

256564 is a wasteful number, since it uses less digits than its factorization.

256564 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53 (or 37 counting only the distinct ones).

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

The square root of 256564 is about 506.5214704235. The cubic root of 256564 is about 63.5426377826.

It can be divided in two parts, 256 and 564, that added together give a triangular number (820 = T₄₀).

The spelling of 256564 in words is "two hundred fifty-six thousand, five hundred sixty-four".