778105664 has 56 divisors (see below), whose sum is σ = 1770522240. Its totient is φ = 332361216.

The previous prime is 778105637. The next prime is 778105739. The reversal of 778105664 is 466501877.

It is a tau number, because it is divible by the number of its divisors (56).

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 139277 + ... + 144755.

Almost surely, 2^778105664 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 778105664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (885261120).

778105664 is an abundant number, since it is smaller than the sum of its proper divisors (992416576).

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

778105664 is a wasteful number, since it uses less digits than its factorization.

778105664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5815 (or 5805 counting only the distinct ones).

The product of its (nonzero) digits is 282240, while the sum is 44.

The square root of 778105664 is about 27894.5454166222. The cubic root of 778105664 is about 919.7706044323.

The spelling of 778105664 in words is "seven hundred seventy-eight million, one hundred five thousand, six hundred sixty-four".