20111111222121 has 6 divisors (see below), whose sum is σ = 29049382876410. Its totient is φ = 13407407481408.

The previous prime is 20111111222113. The next prime is 20111111222123. The reversal of 20111111222121 is 12122211111102.

It is a happy number.

20111111222121 is a `hidden beast` number, since 201 + 11 + 111 + 222 + 121 = 666.

It can be written as a sum of positive squares in only one way, i.e., 18217625140521 + 1893486081600 = 4268211^2 + 1376040^2 .

It is not a de Polignac number, because 20111111222121 - 2³ = 20111111222113 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20111111222094 and 20111111222103.

It is not an unprimeable number, because it can be changed into a prime (20111111222123) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1117283956776 + ... + 1117283956793.

It is an arithmetic number, because the mean of its divisors is an integer number (4841563812735).

Almost surely, 2^{20111111222121} is an apocalyptic number.

It is an amenable number.

20111111222121 is a deficient number, since it is larger than the sum of its proper divisors (8938271654289).

20111111222121 is a wasteful number, since it uses less digits than its factorization.

20111111222121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2234567913575 (or 2234567913572 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 18.

Adding to 20111111222121 its reverse (12122211111102), we get a palindrome (32233322333223).

The spelling of 20111111222121 in words is "twenty trillion, one hundred eleven billion, one hundred eleven million, two hundred twenty-two thousand, one hundred twenty-one".