20811884 has 6 divisors (see below), whose sum is σ = 36420804. Its totient is φ = 10405940.

The previous prime is 20811883. The next prime is 20811899. The reversal of 20811884 is 48811802.

It is a self number, because there is not a number n which added to its sum of digits gives 20811884.

It is not an unprimeable number, because it can be changed into a prime (20811883) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2601482 + ... + 2601489.

It is an arithmetic number, because the mean of its divisors is an integer number (6070134).

Almost surely, 2^20811884 is an apocalyptic number.

It is an amenable number.

20811884 is a deficient number, since it is larger than the sum of its proper divisors (15608920).

20811884 is a wasteful number, since it uses less digits than its factorization.

20811884 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5202975 (or 5202973 counting only the distinct ones).

The product of its (nonzero) digits is 4096, while the sum is 32.

The square root of 20811884 is about 4562.0043840400. The cubic root of 20811884 is about 275.0661394636.

The spelling of 20811884 in words is "twenty million, eight hundred eleven thousand, eight hundred eighty-four".