256778286 has 8 divisors (see below), whose sum is σ = 513556584. Its totient is φ = 85592760.

The previous prime is 256778273. The next prime is 256778311. The reversal of 256778286 is 682877652.

It is a happy number.

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

256778286 is an admirable number.

It is a super-2 number, since 2×256778286² = 131870176322195592, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 21398185 + ... + 21398196.

It is an arithmetic number, because the mean of its divisors is an integer number (64194573).

Almost surely, 2^256778286 is an apocalyptic number.

256778286 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

256778286 is a wasteful number, since it uses less digits than its factorization.

256778286 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42796386.

The product of its digits is 2257920, while the sum is 51.

The square root of 256778286 is about 16024.3029801611. The cubic root of 256778286 is about 635.6032343950.

The spelling of 256778286 in words is "two hundred fifty-six million, seven hundred seventy-eight thousand, two hundred eighty-six".