20818818 has 24 divisors (see below), whose sum is σ = 47069568. Its totient is φ = 6637752.

The previous prime is 20818789. The next prime is 20818859. The reversal of 20818818 is 81881802.

It is a happy number.

It is an unprimeable number.

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 11 ways as a sum of consecutive naturals, for example, 24730 + ... + 25557.

It is an arithmetic number, because the mean of its divisors is an integer number (1961232).

Almost surely, 2^20818818 is an apocalyptic number.

20818818 is an abundant number, since it is smaller than the sum of its proper divisors (26250750).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20818818 is a wasteful number, since it uses less digits than its factorization.

20818818 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 50318 (or 50315 counting only the distinct ones).

The product of its (nonzero) digits is 8192, while the sum is 36.

The square root of 20818818 is about 4562.7642937149. The cubic root of 20818818 is about 275.0966844610.

The spelling of 20818818 in words is "twenty million, eight hundred eighteen thousand, eight hundred eighteen".