256815460 has 48 divisors (see below), whose sum is σ = 596437632. Its totient is φ = 92102400.

The previous prime is 256815443. The next prime is 256815467. The reversal of 256815460 is 64518652.

It is not an unprimeable number, because it can be changed into a prime (256815467) 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, 8065 + ... + 24055.

It is an arithmetic number, because the mean of its divisors is an integer number (12425784).

Almost surely, 2^256815460 is an apocalyptic number.

256815460 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 256815460, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (298218816).

256815460 is an abundant number, since it is smaller than the sum of its proper divisors (339622172).

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

256815460 is a wasteful number, since it uses less digits than its factorization.

256815460 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16084 (or 16082 counting only the distinct ones).

The product of its (nonzero) digits is 57600, while the sum is 37.

The square root of 256815460 is about 16025.4628638302. The cubic root of 256815460 is about 635.6339051796.

The spelling of 256815460 in words is "two hundred fifty-six million, eight hundred fifteen thousand, four hundred sixty".