20813808 has 40 divisors (see below), whose sum is σ = 54064000. Its totient is φ = 6899904.

The previous prime is 20813791. The next prime is 20813813. The reversal of 20813808 is 80831802.

It is a congruent number.

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, 8463 + ... + 10641.

It is an arithmetic number, because the mean of its divisors is an integer number (1351600).

Almost surely, 2^20813808 is an apocalyptic number.

It is an amenable number.

20813808 is an abundant number, since it is smaller than the sum of its proper divisors (33250192).

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

20813808 is a wasteful number, since it uses less digits than its factorization.

20813808 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2389 (or 2383 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 30.

The square root of 20813808 is about 4562.2152513883. The cubic root of 20813808 is about 275.0746155654.

The spelling of 20813808 in words is "twenty million, eight hundred thirteen thousand, eight hundred eight".