256778806 has 16 divisors (see below), whose sum is σ = 406485360. Its totient is φ = 121318560.

The previous prime is 256778803. The next prime is 256778807. The reversal of 256778806 is 608877652.

256778806 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a self number, because there is not a number n which added to its sum of digits gives 256778806.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256778803) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6576 + ... + 23596.

It is an arithmetic number, because the mean of its divisors is an integer number (25405335).

Almost surely, 2^256778806 is an apocalyptic number.

256778806 is a deficient number, since it is larger than the sum of its proper divisors (149706554).

256778806 is a wasteful number, since it uses less digits than its factorization.

256778806 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17439.

The product of its (nonzero) digits is 1128960, while the sum is 49.

The square root of 256778806 is about 16024.3192055076. The cubic root of 256778806 is about 635.6036634466.

The spelling of 256778806 in words is "two hundred fifty-six million, seven hundred seventy-eight thousand, eight hundred six".