256395580 has 48 divisors (see below), whose sum is σ = 618508800. Its totient is φ = 87455808.

The previous prime is 256395569. The next prime is 256395599. The reversal of 256395580 is 85593652.

It is a congruent number.

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 15 ways as a sum of consecutive naturals, for example, 23259 + ... + 32461.

It is an arithmetic number, because the mean of its divisors is an integer number (12885600).

Almost surely, 2^256395580 is an apocalyptic number.

256395580 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 256395580, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (309254400).

256395580 is an abundant number, since it is smaller than the sum of its proper divisors (362113220).

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

256395580 is a wasteful number, since it uses less digits than its factorization.

256395580 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9418 (or 9416 counting only the distinct ones).

The product of its (nonzero) digits is 324000, while the sum is 43.

The square root of 256395580 is about 16012.3571031875. The cubic root of 256395580 is about 635.2873066963.

The spelling of 256395580 in words is "two hundred fifty-six million, three hundred ninety-five thousand, five hundred eighty".