256655520 has 288 divisors, whose sum is σ = 989392320. Its totient is φ = 62092800.

The previous prime is 256655491. The next prime is 256655527. The reversal of 256655520 is 25556652.

256655520 is a `hidden beast` number, since 25 + 66 + 55 + 520 = 666.

It is a tau number, because it is divible by the number of its divisors (288).

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

It is not an unprimeable number, because it can be changed into a prime (256655527) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 522475 + ... + 522965.

It is an arithmetic number, because the mean of its divisors is an integer number (3435390).

Almost surely, 2^256655520 is an apocalyptic number.

256655520 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 256655520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (494696160).

256655520 is an abundant number, since it is smaller than the sum of its proper divisors (732736800).

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

256655520 is a wasteful number, since it uses less digits than its factorization.

256655520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 537 (or 512 counting only the distinct ones).

The product of its (nonzero) digits is 90000, while the sum is 36.

The square root of 256655520 is about 16020.4719031619. The cubic root of 256655520 is about 635.5019240302.

The spelling of 256655520 in words is "two hundred fifty-six million, six hundred fifty-five thousand, five hundred twenty".