20123340021 has 24 divisors (see below), whose sum is σ = 31927197120. Its totient is φ = 12156889536.

The previous prime is 20123339987. The next prime is 20123340043. The reversal of 20123340021 is 12004332102.

It is not a de Polignac number, because 20123340021 - 2⁷ = 20123339893 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 20123339976 and 20123340003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20123340071) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2554336 + ... + 2562201.

It is an arithmetic number, because the mean of its divisors is an integer number (1330299880).

Almost surely, 2^20123340021 is an apocalyptic number.

It is an amenable number.

20123340021 is a deficient number, since it is larger than the sum of its proper divisors (11803857099).

20123340021 is a wasteful number, since it uses less digits than its factorization.

20123340021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5116585 (or 5116582 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 18.

Adding to 20123340021 its reverse (12004332102), we get a palindrome (32127672123).

The spelling of 20123340021 in words is "twenty billion, one hundred twenty-three million, three hundred forty thousand, twenty-one".