779749920 has 144 divisors (see below), whose sum is σ = 2678621400. Its totient is φ = 206548992.

The previous prime is 779749909. The next prime is 779749963. The reversal of 779749920 is 29947977.

It can be written as a sum of positive squares in 4 ways, for example, as 281031696 + 498718224 = 16764^2 + 22332^2 .

It is a tau number, because it is divible by the number of its divisors (144).

It is a Smith number, since the sum of its digits (54) coincides with the sum of the digits of its prime factors.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 224356 + ... + 227804.

Almost surely, 2^779749920 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 779749920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1339310700).

779749920 is an abundant number, since it is smaller than the sum of its proper divisors (1898871480).

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

779749920 is a wasteful number, since it uses less digits than its factorization.

779749920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3627 (or 3616 counting only the distinct ones).

The product of its (nonzero) digits is 2000376, while the sum is 54.

The square root of 779749920 is about 27924.0025784270. The cubic root of 779749920 is about 920.4180204952.

The spelling of 779749920 in words is "seven hundred seventy-nine million, seven hundred forty-nine thousand, nine hundred twenty".