256978585 has 8 divisors (see below), whose sum is σ = 308891016. Its totient is φ = 205238400.

The previous prime is 256978573. The next prime is 256978619. The reversal of 256978585 is 585879652.

It can be written as a sum of positive squares in 4 ways, for example, as 104530176 + 152448409 = 10224^2 + 12347^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 256978585 - 2¹¹ = 256976537 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 39754 + ... + 45763.

It is an arithmetic number, because the mean of its divisors is an integer number (38611377).

Almost surely, 2^256978585 is an apocalyptic number.

It is an amenable number.

256978585 is a deficient number, since it is larger than the sum of its proper divisors (51912431).

256978585 is an equidigital number, since it uses as much as digits as its factorization.

256978585 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 86123.

The product of its digits is 6048000, while the sum is 55.

The square root of 256978585 is about 16030.5516124680. The cubic root of 256978585 is about 635.7684581318.

The spelling of 256978585 in words is "two hundred fifty-six million, nine hundred seventy-eight thousand, five hundred eighty-five".