778705040 has 20 divisors (see below), whose sum is σ = 1810489404. Its totient is φ = 311481984.

The previous prime is 778704989. The next prime is 778705153. The reversal of 778705040 is 40507877.

It can be written as a sum of positive squares in 2 ways, for example, as 273174784 + 505530256 = 16528^2 + 22484^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a junction number, because it is equal to n+sod(n) for n = 778704985 and 778705003.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4866827 + ... + 4866986.

Almost surely, 2^778705040 is an apocalyptic number.

It is an amenable number.

778705040 is an abundant number, since it is smaller than the sum of its proper divisors (1031784364).

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

778705040 is a wasteful number, since it uses less digits than its factorization.

778705040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9733826 (or 9733820 counting only the distinct ones).

The product of its (nonzero) digits is 54880, while the sum is 38.

The square root of 778705040 is about 27905.2869542673. The cubic root of 778705040 is about 920.0067107261.

The spelling of 778705040 in words is "seven hundred seventy-eight million, seven hundred five thousand, forty".