778771920 has 80 divisors (see below), whose sum is σ = 2417380992. Its totient is φ = 207398400.

The previous prime is 778771907. The next prime is 778771963. The reversal of 778771920 is 29177877.

778771920 is digitally balanced in base 6, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (80).

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a self number, because there is not a number n which added to its sum of digits gives 778771920.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 234270 + ... + 237570.

Almost surely, 2^778771920 is an apocalyptic number.

It is an amenable number.

778771920 is an abundant number, since it is smaller than the sum of its proper divisors (1638609072).

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

778771920 is a wasteful number, since it uses less digits than its factorization.

778771920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4300 (or 4294 counting only the distinct ones).

The product of its (nonzero) digits is 345744, while the sum is 48.

The square root of 778771920 is about 27906.4852677653. The cubic root of 778771920 is about 920.0330485923.

It can be divided in two parts, 77877 and 1920, that added together give a palindrome (79797).

The spelling of 778771920 in words is "seven hundred seventy-eight million, seven hundred seventy-one thousand, nine hundred twenty".