256673778 has 8 divisors (see below), whose sum is σ = 513347568. Its totient is φ = 85557924.

The previous prime is 256673771. The next prime is 256673779. The reversal of 256673778 is 877376652.

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

256673778 is an admirable number.

It is a Smith number, since the sum of its digits (51) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a self number, because there is not a number n which added to its sum of digits gives 256673778.

It is not an unprimeable number, because it can be changed into a prime (256673771) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21389476 + ... + 21389487.

It is an arithmetic number, because the mean of its divisors is an integer number (64168446).

Almost surely, 2^256673778 is an apocalyptic number.

256673778 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.

256673778 is a wasteful number, since it uses less digits than its factorization.

256673778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42778968.

The product of its digits is 2963520, while the sum is 51.

The square root of 256673778 is about 16021.0417264297. The cubic root of 256673778 is about 635.5169931509.

The spelling of 256673778 in words is "two hundred fifty-six million, six hundred seventy-three thousand, seven hundred seventy-eight".