20811133 has 12 divisors (see below), whose sum is σ = 24328512. Its totient is φ = 17750040.

The previous prime is 20811127. The next prime is 20811143. The reversal of 20811133 is 33111802.

It is not a de Polignac number, because 20811133 - 2⁵ = 20811101 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20811133.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20811103) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 10188 + ... + 12058.

It is an arithmetic number, because the mean of its divisors is an integer number (2027376).

Almost surely, 2^20811133 is an apocalyptic number.

It is an amenable number.

20811133 is a deficient number, since it is larger than the sum of its proper divisors (3517379).

20811133 is a wasteful number, since it uses less digits than its factorization.

20811133 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2112 (or 2105 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 19.

The square root of 20811133 is about 4561.9220729863. The cubic root of 20811133 is about 275.0628308227.

Adding to 20811133 its reverse (33111802), we get a palindrome (53922935).

The spelling of 20811133 in words is "twenty million, eight hundred eleven thousand, one hundred thirty-three".