256355730 has 48 divisors (see below), whose sum is σ = 670249944. Its totient is φ = 67979520.

The previous prime is 256355717. The next prime is 256355731. The reversal of 256355730 is 37553652.

256355730 is a `hidden beast` number, since 2 + 56 + 35 + 573 + 0 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 183304521 + 73051209 = 13539^2 + 8547^2 .

It is not an unprimeable number, because it can be changed into a prime (256355731) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 8422 + ... + 24158.

Almost surely, 2^256355730 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 256355730, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (335124972).

256355730 is an abundant number, since it is smaller than the sum of its proper divisors (413894214).

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

256355730 is a wasteful number, since it uses less digits than its factorization.

256355730 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15931 (or 15928 counting only the distinct ones).

The product of its (nonzero) digits is 94500, while the sum is 36.

The square root of 256355730 is about 16011.1127033695. The cubic root of 256355730 is about 635.2543920482.

The spelling of 256355730 in words is "two hundred fifty-six million, three hundred fifty-five thousand, seven hundred thirty".