256355240 has 128 divisors (see below), whose sum is σ = 655983360. Its totient is φ = 89616384.

The previous prime is 256355219. The next prime is 256355243. The reversal of 256355240 is 42553652.

It is a super-3 number, since 3×256355240³ (a number of 26 digits) contains 333 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 256355197 and 256355206.

It is not an unprimeable number, because it can be changed into a prime (256355243) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 578459 + ... + 578901.

It is an arithmetic number, because the mean of its divisors is an integer number (5124870).

Almost surely, 2^256355240 is an apocalyptic number.

256355240 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 256355240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (327991680).

256355240 is an abundant number, since it is smaller than the sum of its proper divisors (399628120).

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

256355240 is a wasteful number, since it uses less digits than its factorization.

256355240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 531 (or 527 counting only the distinct ones).

The product of its (nonzero) digits is 36000, while the sum is 32.

The square root of 256355240 is about 16011.0974014900. The cubic root of 256355240 is about 635.2539873048.

The spelling of 256355240 in words is "two hundred fifty-six million, three hundred fifty-five thousand, two hundred forty".