256788560 has 80 divisors (see below), whose sum is σ = 712025856. Its totient is φ = 84209664.

The previous prime is 256788541. The next prime is 256788563. The reversal of 256788560 is 65887652.

It is a tau number, because it is divible by the number of its divisors (80).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256788563) 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, 2912 + ... + 22848.

Almost surely, 2^256788560 is an apocalyptic number.

256788560 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 256788560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (356012928).

256788560 is an abundant number, since it is smaller than the sum of its proper divisors (455237296).

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

256788560 is a wasteful number, since it uses less digits than its factorization.

256788560 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19980 (or 19974 counting only the distinct ones).

The product of its (nonzero) digits is 806400, while the sum is 47.

The square root of 256788560 is about 16024.6235525207. The cubic root of 256788560 is about 635.6117113586.

The spelling of 256788560 in words is "two hundred fifty-six million, seven hundred eighty-eight thousand, five hundred sixty".