780403664 has 20 divisors (see below), whose sum is σ = 1518819456. Its totient is φ = 388450272.

The previous prime is 780403627. The next prime is 780403681. The reversal of 780403664 is 466304087.

It is a happy number.

It is a Smith number, since the sum of its digits (38) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 105794 + ... + 112929.

Almost surely, 2^780403664 is an apocalyptic number.

It is an amenable number.

780403664 is a deficient number, since it is larger than the sum of its proper divisors (738415792).

780403664 is a wasteful number, since it uses less digits than its factorization.

780403664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 218954 (or 218948 counting only the distinct ones).

The product of its (nonzero) digits is 96768, while the sum is 38.

The square root of 780403664 is about 27935.7058976501. The cubic root of 780403664 is about 920.6751754542.

The spelling of 780403664 in words is "seven hundred eighty million, four hundred three thousand, six hundred sixty-four".