820407656 has 16 divisors (see below), whose sum is σ = 1542328800. Its totient is φ = 409119984.

The previous prime is 820407647. The next prime is 820407673. The reversal of 820407656 is 656704028.

It is a happy number.

820407656 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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, 132260 + ... + 138323.

It is an arithmetic number, because the mean of its divisors is an integer number (96395550).

Almost surely, 2^820407656 is an apocalyptic number.

It is an amenable number.

820407656 is a deficient number, since it is larger than the sum of its proper divisors (721921144).

820407656 is a wasteful number, since it uses less digits than its factorization.

820407656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 270968 (or 270964 counting only the distinct ones).

The product of its (nonzero) digits is 80640, while the sum is 38.

The square root of 820407656 is about 28642.7592246278. The cubic root of 820407656 is about 936.1452431243.

The spelling of 820407656 in words is "eight hundred twenty million, four hundred seven thousand, six hundred fifty-six".