12111111161 has 4 divisors (see below), whose sum is σ = 12111335424. Its totient is φ = 12110886900.

The previous prime is 12111111149. The next prime is 12111111193. The reversal of 12111111161 is 16111111121.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 12111111161 - 2⁶ = 12111111097 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12111111101) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 23816 + ... + 157446.

It is an arithmetic number, because the mean of its divisors is an integer number (3027833856).

Almost surely, 2^12111111161 is an apocalyptic number.

It is an amenable number.

12111111161 is a deficient number, since it is larger than the sum of its proper divisors (224263).

12111111161 is an equidigital number, since it uses as much as digits as its factorization.

12111111161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 224262.

The product of its digits is 12, while the sum is 17.

Adding to 12111111161 its reverse (16111111121), we get a palindrome (28222222282).

The spelling of 12111111161 in words is "twelve billion, one hundred eleven million, one hundred eleven thousand, one hundred sixty-one".