256656566 has 16 divisors (see below), whose sum is σ = 394635456. Its totient is φ = 125131776.

The previous prime is 256656529. The next prime is 256656571. The reversal of 256656566 is 665656652.

256656566 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-3 number, since 3×256656566³ (a number of 26 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (47).

It is a self number, because there is not a number n which added to its sum of digits gives 256656566.

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, 21110 + ... + 30966.

It is an arithmetic number, because the mean of its divisors is an integer number (24664716).

Almost surely, 2^256656566 is an apocalyptic number.

256656566 is a deficient number, since it is larger than the sum of its proper divisors (137978890).

256656566 is a wasteful number, since it uses less digits than its factorization.

256656566 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10183.

The product of its digits is 1944000, while the sum is 47.

The square root of 256656566 is about 16020.5045488586. The cubic root of 256656566 is about 635.5027873587.

The spelling of 256656566 in words is "two hundred fifty-six million, six hundred fifty-six thousand, five hundred sixty-six".