256528720 has 120 divisors (see below), whose sum is σ = 716525568. Its totient is φ = 85075200.

The previous prime is 256528717. The next prime is 256528771. The reversal of 256528720 is 27825652.

It is a self number, because there is not a number n which added to its sum of digits gives 256528720.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 120465 + ... + 122575.

Almost surely, 2^256528720 is an apocalyptic number.

256528720 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 256528720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (358262784).

256528720 is an abundant number, since it is smaller than the sum of its proper divisors (459996848).

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

256528720 is a wasteful number, since it uses less digits than its factorization.

256528720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2169 (or 2156 counting only the distinct ones).

The product of its (nonzero) digits is 67200, while the sum is 37.

The square root of 256528720 is about 16016.5139777668. The cubic root of 256528720 is about 635.3972507597.

The spelling of 256528720 in words is "two hundred fifty-six million, five hundred twenty-eight thousand, seven hundred twenty".