12111221121021 has 64 divisors (see below), whose sum is σ = 20586329210880. Its totient is φ = 6969329640000.

The previous prime is 12111221120987. The next prime is 12111221121047. The reversal of 12111221121021 is 12012112211121.

It is a happy number.

12111221121021 is a `hidden beast` number, since 1 + 211 + 1 + 221 + 1 + 210 + 21 = 666.

It is not a de Polignac number, because 12111221121021 - 2¹⁰ = 12111221119997 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 12111221120985 and 12111221121003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12111221121061) 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, 11921805 + ... + 12897746.

It is an arithmetic number, because the mean of its divisors is an integer number (321661393920).

Almost surely, 2^{12111221121021} is an apocalyptic number.

12111221121021 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

12111221121021 is a deficient number, since it is larger than the sum of its proper divisors (8475108089859).

12111221121021 is a wasteful number, since it uses less digits than its factorization.

12111221121021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24819655 (or 24819649 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 18.

Adding to 12111221121021 its reverse (12012112211121), we get a palindrome (24123333332142).

The spelling of 12111221121021 in words is "twelve trillion, one hundred eleven billion, two hundred twenty-one million, one hundred twenty-one thousand, twenty-one".