820518866 has 8 divisors (see below), whose sum is σ = 1273219020. Its totient is φ = 396112528.

The previous prime is 820518863. The next prime is 820518871. The reversal of 820518866 is 668815028.

820518866 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 819161641 + 1357225 = 28621^2 + 1165^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (820518863) 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, 7073381 + ... + 7073496.

Almost surely, 2^820518866 is an apocalyptic number.

820518866 is a deficient number, since it is larger than the sum of its proper divisors (452700154).

820518866 is a wasteful number, since it uses less digits than its factorization.

820518866 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14146908.

The product of its (nonzero) digits is 184320, while the sum is 44.

The square root of 820518866 is about 28644.7004871756. The cubic root of 820518866 is about 936.1875407991.

The spelling of 820518866 in words is "eight hundred twenty million, five hundred eighteen thousand, eight hundred sixty-six".