20120111111 has 2 divisors, whose sum is σ = 20120111112. Its totient is φ = 20120111110.

The previous prime is 20120111083. The next prime is 20120111149. The reversal of 20120111111 is 11111102102.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20120111111 is a prime.

It is a super-2 number, since 2×20120111111² (a number of 21 digits) contains 22 as substring.

It is a Sophie Germain prime.

20120111111 is a modest number, since divided by 111111 gives 20120 as remainder.

It is a junction number, because it is equal to n+sod(n) for n = 20120111092 and 20120111101.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20120111171) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10060055555 + 10060055556.

It is an arithmetic number, because the mean of its divisors is an integer number (10060055556).

Almost surely, 2^20120111111 is an apocalyptic number.

20120111111 is a deficient number, since it is larger than the sum of its proper divisors (1).

20120111111 is an equidigital number, since it uses as much as digits as its factorization.

20120111111 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4, while the sum is 11.

Adding to 20120111111 its reverse (11111102102), we get a palindrome (31231213213).

Subtracting from 20120111111 its reverse (11111102102), we obtain a palindrome (9009009009).

The spelling of 20120111111 in words is "twenty billion, one hundred twenty million, one hundred eleven thousand, one hundred eleven".