778664 has 16 divisors (see below), whose sum is σ = 1473120. Its totient is φ = 385840.

The previous prime is 778663. The next prime is 778667. The reversal of 778664 is 466877.

778664 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not an unprimeable number, because it can be changed into a prime (778663) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 677 + ... + 1419.

It is an arithmetic number, because the mean of its divisors is an integer number (92070).

2⁷⁷⁸⁶⁶⁴ is an apocalyptic number.

It is an amenable number.

778664 is a deficient number, since it is larger than the sum of its proper divisors (694456).

778664 is a wasteful number, since it uses less digits than its factorization.

778664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 880 (or 876 counting only the distinct ones).

The product of its digits is 56448, while the sum is 38.

The square root of 778664 is about 882.4194014186. The cubic root of 778664 is about 91.9990548107. Note that the first 3 decimals are identical.

The spelling of 778664 in words is "seven hundred seventy-eight thousand, six hundred sixty-four".