256569984 has 256 divisors, whose sum is σ = 876873600. Its totient is φ = 72990720.

The previous prime is 256569883. The next prime is 256570009. The reversal of 256569984 is 489965652.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a self number, because there is not a number n which added to its sum of digits gives 256569984.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 646074 + ... + 646470.

Almost surely, 2^256569984 is an apocalyptic number.

256569984 is a gapful number since it is divisible by the number (24) 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 256569984, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (438436800).

256569984 is an abundant number, since it is smaller than the sum of its proper divisors (620303616).

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

256569984 is a wasteful number, since it uses less digits than its factorization.

256569984 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 448 (or 430 counting only the distinct ones).

The product of its digits is 4665600, while the sum is 54.

The square root of 256569984 is about 16017.8020964176. The cubic root of 256569984 is about 635.4313179348.

The spelling of 256569984 in words is "two hundred fifty-six million, five hundred sixty-nine thousand, nine hundred eighty-four".