256531968 has 320 divisors, whose sum is σ = 950653440. Its totient is φ = 66355200.

The previous prime is 256531927. The next prime is 256531991. The reversal of 256531968 is 869135652.

256531968 is a `hidden beast` number, since 2 + 56 + 531 + 9 + 68 = 666.

256531968 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1064328 + ... + 1064568.

It is an arithmetic number, because the mean of its divisors is an integer number (2970792).

Almost surely, 2^256531968 is an apocalyptic number.

256531968 is a gapful number since it is divisible by the number (28) 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 256531968, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (475326720).

256531968 is an abundant number, since it is smaller than the sum of its proper divisors (694121472).

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

256531968 is a wasteful number, since it uses less digits than its factorization.

256531968 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 286 (or 264 counting only the distinct ones).

The product of its digits is 388800, while the sum is 45.

The square root of 256531968 is about 16016.6153727933. The cubic root of 256531968 is about 635.3999324108.

The spelling of 256531968 in words is "two hundred fifty-six million, five hundred thirty-one thousand, nine hundred sixty-eight".