779686816 has 48 divisors (see below), whose sum is σ = 1570703400. Its totient is φ = 380843008.

The previous prime is 779686813. The next prime is 779686819. The reversal of 779686816 is 618686977.

It is an interprime number because it is at equal distance from previous prime (779686813) and next prime (779686819).

It can be written as a sum of positive squares in 4 ways, for example, as 448592400 + 331094416 = 21180^2 + 18196^2 .

It is not an unprimeable number, because it can be changed into a prime (779686813) 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, 455370 + ... + 457078.

Almost surely, 2^779686816 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 779686816, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (785351700).

779686816 is an abundant number, since it is smaller than the sum of its proper divisors (791016584).

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

779686816 is a wasteful number, since it uses less digits than its factorization.

779686816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2041 (or 2033 counting only the distinct ones).

The product of its digits is 6096384, while the sum is 58.

The square root of 779686816 is about 27922.8726315900. The cubic root of 779686816 is about 920.3931904721.

The spelling of 779686816 in words is "seven hundred seventy-nine million, six hundred eighty-six thousand, eight hundred sixteen".