256563 has 12 divisors (see below), whose sum is σ = 383760. Its totient is φ = 164976.

The previous prime is 256561. The next prime is 256567. The reversal of 256563 is 365652.

256563 is a `hidden beast` number, since 2 + 5 + 656 + 3 = 666.

It is not a de Polignac number, because 256563 - 2¹ = 256561 is a prime.

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

It is a zygodrome in base 3.

It is not an unprimeable number, because it can be changed into a prime (256561) 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 11 ways as a sum of consecutive naturals, for example, 231 + ... + 752.

It is an arithmetic number, because the mean of its divisors is an integer number (31980).

2²⁵⁶⁵⁶³ is an apocalyptic number.

256563 is a deficient number, since it is larger than the sum of its proper divisors (127197).

256563 is a wasteful number, since it uses less digits than its factorization.

256563 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1018 (or 1015 counting only the distinct ones).

The product of its digits is 5400, while the sum is 27.

The square root of 256563 is about 506.5204832976. The cubic root of 256563 is about 63.5425552266.

It can be divided in two parts, 2565 and 63, that added together give a triangular number (2628 = T₇₂).

The spelling of 256563 in words is "two hundred fifty-six thousand, five hundred sixty-three".