20109812 has 12 divisors (see below), whose sum is σ = 35273700. Its totient is φ = 10031616.

The previous prime is 20109811. The next prime is 20109829. The reversal of 20109812 is 21890102.

It can be written as a sum of positive squares in 2 ways, for example, as 8317456 + 11792356 = 2884^2 + 3434^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20109811) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3803 + ... + 7394.

It is an arithmetic number, because the mean of its divisors is an integer number (2939475).

Almost surely, 2^20109812 is an apocalyptic number.

It is an amenable number.

20109812 is a deficient number, since it is larger than the sum of its proper divisors (15163888).

20109812 is a wasteful number, since it uses less digits than its factorization.

20109812 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11650 (or 11648 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 23.

The square root of 20109812 is about 4484.3965034328. The cubic root of 20109812 is about 271.9376479050.

Adding to 20109812 its reverse (21890102), we get a palindrome (41999914).

The spelling of 20109812 in words is "twenty million, one hundred nine thousand, eight hundred twelve".