256577440 has 96 divisors (see below), whose sum is σ = 699560064. Its totient is φ = 87106560.

The previous prime is 256577437. The next prime is 256577473. The reversal of 256577440 is 44775652.

256577440 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a junction number, because it is equal to n+sod(n) for n = 256577393 and 256577402.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 118770 + ... + 120910.

It is an arithmetic number, because the mean of its divisors is an integer number (7287084).

Almost surely, 2^256577440 is an apocalyptic number.

256577440 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 256577440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (349780032).

256577440 is an abundant number, since it is smaller than the sum of its proper divisors (442982624).

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

256577440 is a wasteful number, since it uses less digits than its factorization.

256577440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2270 (or 2262 counting only the distinct ones).

The product of its (nonzero) digits is 235200, while the sum is 40.

The square root of 256577440 is about 16018.0348357718. The cubic root of 256577440 is about 635.4374731495.

The spelling of 256577440 in words is "two hundred fifty-six million, five hundred seventy-seven thousand, four hundred forty".