256805730 has 96 divisors (see below), whose sum is σ = 702477360. Its totient is φ = 64995840.

The previous prime is 256805711. The next prime is 256805743. The reversal of 256805730 is 37508652.

256805730 is a `hidden beast` number, since 2 + 5 + 6 + 80 + 573 + 0 = 666.

It can be written as a sum of positive squares in 8 ways, for example, as 56385081 + 200420649 = 7509^2 + 14157^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 158404 + ... + 160016.

Almost surely, 2^256805730 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 256805730, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (351238680).

256805730 is an abundant number, since it is smaller than the sum of its proper divisors (445671630).

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

256805730 is a wasteful number, since it uses less digits than its factorization.

256805730 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1716 (or 1713 counting only the distinct ones).

The product of its (nonzero) digits is 50400, while the sum is 36.

The square root of 256805730 is about 16025.1592815797. The cubic root of 256805730 is about 635.6258776307.

The spelling of 256805730 in words is "two hundred fifty-six million, eight hundred five thousand, seven hundred thirty".