256906728 has 80 divisors (see below), whose sum is σ = 774954180. Its totient is φ = 79045632.

The previous prime is 256906717. The next prime is 256906729. The reversal of 256906728 is 827609652.

256906728 is a `hidden beast` number, since 2 + 569 + 0 + 67 + 28 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 256064004 + 842724 = 16002^2 + 918^2 .

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (256906729) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 6825 + ... + 23672.

Almost surely, 2^256906728 is an apocalyptic number.

It is an amenable number.

256906728 is an abundant number, since it is smaller than the sum of its proper divisors (518047452).

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

256906728 is a wasteful number, since it uses less digits than its factorization.

256906728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30528 (or 30515 counting only the distinct ones).

The product of its (nonzero) digits is 362880, while the sum is 45.

The square root of 256906728 is about 16028.3102041357. The cubic root of 256906728 is about 635.7091942144.

The spelling of 256906728 in words is "two hundred fifty-six million, nine hundred six thousand, seven hundred twenty-eight".