8720866 has 16 divisors (see below), whose sum is σ = 16309440. Its totient is φ = 3397680.

The previous prime is 8720839. The next prime is 8720891. The reversal of 8720866 is 6680278.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 28161 + ... + 28468.

It is an arithmetic number, because the mean of its divisors is an integer number (1019340).

Almost surely, 2^8720866 is an apocalyptic number.

8720866 is a deficient number, since it is larger than the sum of its proper divisors (7588574).

8720866 is a wasteful number, since it uses less digits than its factorization.

8720866 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 56649.

The product of its (nonzero) digits is 32256, while the sum is 37.

The square root of 8720866 is about 2953.1112407087. Note that the first 3 decimals coincide. The cubic root of 8720866 is about 205.8353068302.

The spelling of 8720866 in words is "eight million, seven hundred twenty thousand, eight hundred sixty-six".