256185240 has 128 divisors (see below), whose sum is σ = 840222720. Its totient is φ = 62208000.

The previous prime is 256185157. The next prime is 256185263. The reversal of 256185240 is 42581652.

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 31 ways as a sum of consecutive naturals, for example, 61215 + ... + 65265.

It is an arithmetic number, because the mean of its divisors is an integer number (6564240).

Almost surely, 2^256185240 is an apocalyptic number.

256185240 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 256185240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (420111360).

256185240 is an abundant number, since it is smaller than the sum of its proper divisors (584037480).

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

256185240 is a wasteful number, since it uses less digits than its factorization.

256185240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4113 (or 4109 counting only the distinct ones).

The product of its (nonzero) digits is 19200, while the sum is 33.

The square root of 256185240 is about 16005.7877032029. The cubic root of 256185240 is about 635.1135349930.

The spelling of 256185240 in words is "two hundred fifty-six million, one hundred eighty-five thousand, two hundred forty".