256501440 has 504 divisors, whose sum is σ = 1044171648. Its totient is φ = 57507840.

The previous prime is 256501429. The next prime is 256501447. The reversal of 256501440 is 44105652.

256501440 is a `hidden beast` number, since 2 + 5 + 650 + 1 + 4 + 4 + 0 = 666.

256501440 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not an unprimeable number, because it can be changed into a prime (256501447) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 8274225 + ... + 8274255.

Almost surely, 2^256501440 is an apocalyptic number.

256501440 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 256501440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (522085824).

256501440 is an abundant number, since it is smaller than the sum of its proper divisors (787670208).

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

256501440 is a wasteful number, since it uses less digits than its factorization.

256501440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 97 (or 71 counting only the distinct ones).

The product of its (nonzero) digits is 4800, while the sum is 27.

The square root of 256501440 is about 16015.6623341028. The cubic root of 256501440 is about 635.3747266391.

The spelling of 256501440 in words is "two hundred fifty-six million, five hundred one thousand, four hundred forty".