256438120 has 64 divisors (see below), whose sum is σ = 596776320. Its totient is φ = 99097344.

The previous prime is 256438069. The next prime is 256438121. The reversal of 256438120 is 21834652.

It is not an unprimeable number, because it can be changed into a prime (256438121) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 240709 + ... + 241771.

It is an arithmetic number, because the mean of its divisors is an integer number (9324630).

Almost surely, 2^256438120 is an apocalyptic number.

256438120 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 256438120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (298388160).

256438120 is an abundant number, since it is smaller than the sum of its proper divisors (340338200).

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

256438120 is a wasteful number, since it uses less digits than its factorization.

256438120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1274 (or 1270 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 31.

The square root of 256438120 is about 16013.6853971845. The cubic root of 256438120 is about 635.3224394230.

The spelling of 256438120 in words is "two hundred fifty-six million, four hundred thirty-eight thousand, one hundred twenty".