256245840 has 120 divisors (see below), whose sum is σ = 863516160. Its totient is φ = 68097792.

The previous prime is 256245809. The next prime is 256245851. The reversal of 256245840 is 48542652.

It is a happy number.

256245840 is a `hidden beast` number, since 2 + 56 + 24 + 584 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (120).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 256245795 and 256245804.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 344509 + ... + 345251.

It is an arithmetic number, because the mean of its divisors is an integer number (7195968).

Almost surely, 2^256245840 is an apocalyptic number.

256245840 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 256245840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (431758080).

256245840 is an abundant number, since it is smaller than the sum of its proper divisors (607270320).

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

256245840 is a wasteful number, since it uses less digits than its factorization.

256245840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1241 (or 1232 counting only the distinct ones).

The product of its (nonzero) digits is 76800, while the sum is 36.

The square root of 256245840 is about 16007.6806564849. The cubic root of 256245840 is about 635.1636092360.

The spelling of 256245840 in words is "two hundred fifty-six million, two hundred forty-five thousand, eight hundred forty".