778857664 has 28 divisors (see below), whose sum is σ = 1664435584. Its totient is φ = 359472384.

The previous prime is 778857649. The next prime is 778857679. The reversal of 778857664 is 466758877.

It is an interprime number because it is at equal distance from previous prime (778857649) and next prime (778857679).

It is a junction number, because it is equal to n+sod(n) for n = 778857599 and 778857608.

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, 467232 + ... + 468895.

It is an arithmetic number, because the mean of its divisors is an integer number (59444128).

Almost surely, 2^778857664 is an apocalyptic number.

It is an amenable number.

778857664 is an abundant number, since it is smaller than the sum of its proper divisors (885577920).

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

778857664 is a wasteful number, since it uses less digits than its factorization.

778857664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 936152 (or 936142 counting only the distinct ones).

The product of its digits is 15805440, while the sum is 58.

The square root of 778857664 is about 27908.0214992034. The cubic root of 778857664 is about 920.0668130431.

The spelling of 778857664 in words is "seven hundred seventy-eight million, eight hundred fifty-seven thousand, six hundred sixty-four".