256905584 has 80 divisors (see below), whose sum is σ = 566963712. Its totient is φ = 111876864.

The previous prime is 256905569. The next prime is 256905599. The reversal of 256905584 is 485509652.

It is an interprime number because it is at equal distance from previous prime (256905569) and next prime (256905599).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 396749 + ... + 397395.

Almost surely, 2^256905584 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 256905584, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (283481856).

256905584 is an abundant number, since it is smaller than the sum of its proper divisors (310058128).

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

256905584 is a wasteful number, since it uses less digits than its factorization.

256905584 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 774 (or 768 counting only the distinct ones).

The product of its (nonzero) digits is 432000, while the sum is 44.

The square root of 256905584 is about 16028.2745172398. The cubic root of 256905584 is about 635.7082506133.

The spelling of 256905584 in words is "two hundred fifty-six million, nine hundred five thousand, five hundred eighty-four".