20808912 has 40 divisors (see below), whose sum is σ = 54371520. Its totient is φ = 6856960.

The previous prime is 20808889. The next prime is 20808919. The reversal of 20808912 is 21980802.

It is a self number, because there is not a number n which added to its sum of digits gives 20808912.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20808919) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1837 + ... + 6707.

It is an arithmetic number, because the mean of its divisors is an integer number (1359288).

Almost surely, 2^20808912 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20808912, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27185760).

20808912 is an abundant number, since it is smaller than the sum of its proper divisors (33562608).

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

20808912 is a wasteful number, since it uses less digits than its factorization.

20808912 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4971 (or 4965 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 30.

The square root of 20808912 is about 4561.6786383962. The cubic root of 20808912 is about 275.0530454147.

The spelling of 20808912 in words is "twenty million, eight hundred eight thousand, nine hundred twelve".