12111100111221 has 64 divisors (see below), whose sum is σ = 16929511449600. Its totient is φ = 7694304224256.

The previous prime is 12111100111213. The next prime is 12111100111261. The reversal of 12111100111221 is 12211100111121.

It is not a de Polignac number, because 12111100111221 - 2³ = 12111100111213 is a prime.

It is a super-2 number, since 2×12111100111221² (a number of 27 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 12111100111221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12111100111211) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 556233091 + ... + 556254863.

It is an arithmetic number, because the mean of its divisors is an integer number (264523616400).

Almost surely, 2^{12111100111221} is an apocalyptic number.

It is an amenable number.

12111100111221 is a deficient number, since it is larger than the sum of its proper divisors (4818411338379).

12111100111221 is a wasteful number, since it uses less digits than its factorization.

12111100111221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22398.

The product of its (nonzero) digits is 8, while the sum is 15.

Adding to 12111100111221 its reverse (12211100111121), we get a palindrome (24322200222342).

The spelling of 12111100111221 in words is "twelve trillion, one hundred eleven billion, one hundred million, one hundred eleven thousand, two hundred twenty-one".