256352640 has 256 divisors, whose sum is σ = 869529600. Its totient is φ = 64143360.

The previous prime is 256352599. The next prime is 256352651. The reversal of 256352640 is 46253652.

256352640 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, 3511644 + ... + 3511716.

It is an arithmetic number, because the mean of its divisors is an integer number (3396600).

Almost surely, 2^256352640 is an apocalyptic number.

256352640 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 256352640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (434764800).

256352640 is an abundant number, since it is smaller than the sum of its proper divisors (613176960).

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

256352640 is a wasteful number, since it uses less digits than its factorization.

256352640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 185 (or 173 counting only the distinct ones).

The product of its (nonzero) digits is 43200, while the sum is 33.

The square root of 256352640 is about 16011.0162075991. The cubic root of 256352640 is about 635.2518396782.

The spelling of 256352640 in words is "two hundred fifty-six million, three hundred fifty-two thousand, six hundred forty".