779968640 has 128 divisors (see below), whose sum is σ = 2123003520. Its totient is φ = 271237120.

The previous prime is 779968627. The next prime is 779968643. The reversal of 779968640 is 46869977.

It is a tau number, because it is divible by the number of its divisors (128).

It is not an unprimeable number, because it can be changed into a prime (779968643) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 159512 + ... + 164328.

It is an arithmetic number, because the mean of its divisors is an integer number (16585965).

Almost surely, 2^779968640 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 779968640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1061501760).

779968640 is an abundant number, since it is smaller than the sum of its proper divisors (1343034880).

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

779968640 is a wasteful number, since it uses less digits than its factorization.

779968640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4870 (or 4858 counting only the distinct ones).

The product of its (nonzero) digits is 4572288, while the sum is 56.

The square root of 779968640 is about 27927.9186478334. The cubic root of 779968640 is about 920.5040715929.

The spelling of 779968640 in words is "seven hundred seventy-nine million, nine hundred sixty-eight thousand, six hundred forty".