20811105 has 24 divisors (see below), whose sum is σ = 41226432. Its totient is φ = 9513504.

The previous prime is 20811103. The next prime is 20811121. The reversal of 20811105 is 50111802.

It is not a de Polignac number, because 20811105 - 2¹ = 20811103 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (20811101) by changing a digit.

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 23 ways as a sum of consecutive naturals, for example, 32719 + ... + 33348.

It is an arithmetic number, because the mean of its divisors is an integer number (1717768).

Almost surely, 2^20811105 is an apocalyptic number.

It is an amenable number.

20811105 is a deficient number, since it is larger than the sum of its proper divisors (20415327).

20811105 is a wasteful number, since it uses less digits than its factorization.

20811105 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 66085 (or 66082 counting only the distinct ones).

The product of its (nonzero) digits is 80, while the sum is 18.

The square root of 20811105 is about 4561.9190041034. The cubic root of 20811105 is about 275.0627074630.

Adding to 20811105 its reverse (50111802), we get a palindrome (70922907).

The spelling of 20811105 in words is "twenty million, eight hundred eleven thousand, one hundred five".