256385670 has 32 divisors (see below), whose sum is σ = 651522528. Its totient is φ = 64347648.

The previous prime is 256385599. The next prime is 256385671. The reversal of 256385670 is 76583652.

It is a super-2 number, since 2×256385670² = 131467223562697800, which contains 22 as substring.

It is an alternating number because its digits alternate between even and odd.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256385671) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 250849 + ... + 251868.

It is an arithmetic number, because the mean of its divisors is an integer number (20360079).

Almost surely, 2^256385670 is an apocalyptic number.

256385670 is an abundant number, since it is smaller than the sum of its proper divisors (395136858).

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

256385670 is a wasteful number, since it uses less digits than its factorization.

256385670 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 502744.

The product of its (nonzero) digits is 302400, while the sum is 42.

The square root of 256385670 is about 16012.0476516903. The cubic root of 256385670 is about 635.2791217159.

The spelling of 256385670 in words is "two hundred fifty-six million, three hundred eighty-five thousand, six hundred seventy".