256779813 has 16 divisors (see below), whose sum is σ = 362398400. Its totient is φ = 161274240.

The previous prime is 256779793. The next prime is 256779823. The reversal of 256779813 is 318977652.

256779813 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 256779813 - 2⁸ = 256779557 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256779823) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2128 + ... + 22761.

It is an arithmetic number, because the mean of its divisors is an integer number (22649900).

Almost surely, 2^256779813 is an apocalyptic number.

It is an amenable number.

256779813 is a deficient number, since it is larger than the sum of its proper divisors (105618587).

256779813 is a wasteful number, since it uses less digits than its factorization.

256779813 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25092.

The product of its digits is 635040, while the sum is 48.

The square root of 256779813 is about 16024.3506264685. The cubic root of 256779813 is about 635.6044943201.

The spelling of 256779813 in words is "two hundred fifty-six million, seven hundred seventy-nine thousand, eight hundred thirteen".