256560840 has 48 divisors (see below), whose sum is σ = 833823900. Its totient is φ = 68416128.

The previous prime is 256560839. The next prime is 256560841. The reversal of 256560840 is 48065652.

256560840 is a `hidden beast` number, since 2 + 5 + 6 + 5 + 608 + 40 = 666.

It is an interprime number because it is at equal distance from previous prime (256560839) and next prime (256560841).

It can be written as a sum of positive squares in 2 ways, for example, as 247307076 + 9253764 = 15726^2 + 3042^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 256560795 and 256560804.

It is not an unprimeable number, because it can be changed into a prime (256560841) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 355975 + ... + 356694.

Almost surely, 2^256560840 is an apocalyptic number.

256560840 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

256560840 is an abundant number, since it is smaller than the sum of its proper divisors (577263060).

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

256560840 is a wasteful number, since it uses less digits than its factorization.

256560840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 712686 (or 712679 counting only the distinct ones).

The product of its (nonzero) digits is 57600, while the sum is 36.

The square root of 256560840 is about 16017.5166614554. The cubic root of 256560840 is about 635.4237690484.

The spelling of 256560840 in words is "two hundred fifty-six million, five hundred sixty thousand, eight hundred forty".