12011221111 has 2 divisors, whose sum is σ = 12011221112. Its totient is φ = 12011221110.

The previous prime is 12011221109. The next prime is 12011221129. The reversal of 12011221111 is 11112211021.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 12011221111 - 2¹ = 12011221109 is a prime.

Together with 12011221109, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 12011221091 and 12011221100.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12011221151) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6005610555 + 6005610556.

It is an arithmetic number, because the mean of its divisors is an integer number (6005610556).

Almost surely, 2^12011221111 is an apocalyptic number.

12011221111 is a deficient number, since it is larger than the sum of its proper divisors (1).

12011221111 is an equidigital number, since it uses as much as digits as its factorization.

12011221111 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8, while the sum is 13.

Adding to 12011221111 its reverse (11112211021), we get a palindrome (23123432132).

The spelling of 12011221111 in words is "twelve billion, eleven million, two hundred twenty-one thousand, one hundred eleven".