20121111121111 has 144 divisors (see below), whose sum is σ = 28599298560000. Its totient is φ = 13977350150400.

The previous prime is 20121111121103. The next prime is 20121111121117. The reversal of 20121111121111 is 11112111112102.

It is not a de Polignac number, because 20121111121111 - 2³ = 20121111121103 is a prime.

It is a super-2 number, since 2×20121111121111² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20121111121117) by changing a digit.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 1437317890 + ... + 1437331888.

It is an arithmetic number, because the mean of its divisors is an integer number (198606240000).

Almost surely, 2^{20121111121111} is an apocalyptic number.

20121111121111 is a deficient number, since it is larger than the sum of its proper divisors (8478187438889).

20121111121111 is a wasteful number, since it uses less digits than its factorization.

20121111121111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14590 (or 14570 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 16.

Adding to 20121111121111 its reverse (11112111112102), we get a palindrome (31233222233213).

Subtracting from 20121111121111 its reverse (11112111112102), we obtain a palindrome (9009000009009).

The spelling of 20121111121111 in words is "twenty trillion, one hundred twenty-one billion, one hundred eleven million, one hundred twenty-one thousand, one hundred eleven".