780820864 has 16 divisors (see below), whose sum is σ = 1555541820. Its totient is φ = 390410368.

The previous prime is 780820861. The next prime is 780820871. The reversal of 780820864 is 468028087.

It is a tau number, because it is divible by the number of its divisors (16).

It is a self number, because there is not a number n which added to its sum of digits gives 780820864.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (780820861) by changing a digit.

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 as a sum of consecutive naturals, namely, 3049954 + ... + 3050209.

Almost surely, 2^780820864 is an apocalyptic number.

It is an amenable number.

780820864 is a deficient number, since it is larger than the sum of its proper divisors (774720956).

780820864 is an equidigital number, since it uses as much as digits as its factorization.

780820864 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6100177 (or 6100165 counting only the distinct ones).

The product of its (nonzero) digits is 172032, while the sum is 43.

The square root of 780820864 is about 27943.1720461368. The cubic root of 780820864 is about 920.8392090496.

The spelling of 780820864 in words is "seven hundred eighty million, eight hundred twenty thousand, eight hundred sixty-four".