20390866 has 8 divisors (see below), whose sum is σ = 30827520. Its totient is φ = 10115028.

The previous prime is 20390863. The next prime is 20390873. The reversal of 20390866 is 66809302.

It is a happy number.

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 (20390861) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 39886 + ... + 40393.

It is an arithmetic number, because the mean of its divisors is an integer number (3853440).

Almost surely, 2^20390866 is an apocalyptic number.

20390866 is a deficient number, since it is larger than the sum of its proper divisors (10436654).

20390866 is a wasteful number, since it uses less digits than its factorization.

20390866 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 80408.

The product of its (nonzero) digits is 15552, while the sum is 34.

The square root of 20390866 is about 4515.6246522491. The cubic root of 20390866 is about 273.1986549813.

The spelling of 20390866 in words is "twenty million, three hundred ninety thousand, eight hundred sixty-six".