20112111111 has 4 divisors (see below), whose sum is σ = 26816148152. Its totient is φ = 13408074072.

The previous prime is 20112111109. The next prime is 20112111157. The reversal of 20112111111 is 11111121102.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 20112111111 - 2¹ = 20112111109 is a prime.

It is a Duffinian number.

20112111111 is a modest number, since divided by 111111 gives 20112 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20112101111) 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, 3352018516 + ... + 3352018521.

It is an arithmetic number, because the mean of its divisors is an integer number (6704037038).

Almost surely, 2^20112111111 is an apocalyptic number.

20112111111 is a deficient number, since it is larger than the sum of its proper divisors (6704037041).

20112111111 is an equidigital number, since it uses as much as digits as its factorization.

20112111111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6704037040.

The product of its (nonzero) digits is 4, while the sum is 12.

Adding to 20112111111 its reverse (11111121102), we get a palindrome (31223232213).

Subtracting from 20112111111 its reverse (11111121102), we obtain a palindrome (9000990009).

The spelling of 20112111111 in words is "twenty billion, one hundred twelve million, one hundred eleven thousand, one hundred eleven".