12111221211021 has 24 divisors (see below), whose sum is σ = 17863072526520. Its totient is φ = 7905414606336.

The previous prime is 12111221210987. The next prime is 12111221211071. The reversal of 12111221211021 is 12011212211121.

It is a happy number.

12111221211021 is a `hidden beast` number, since 1 + 211 + 1 + 221 + 211 + 0 + 21 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 4222346877225 + 7888874333796 = 2054835^2 + 2808714^2 .

It is not a de Polignac number, because 12111221211021 - 2³⁸ = 11836343304077 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 12111221210985 and 12111221211003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12111221211071) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 67187826 + ... + 67367843.

It is an arithmetic number, because the mean of its divisors is an integer number (744294688605).

Almost surely, 2^{12111221211021} is an apocalyptic number.

It is an amenable number.

12111221211021 is a deficient number, since it is larger than the sum of its proper divisors (5751851315499).

12111221211021 is a wasteful number, since it uses less digits than its factorization.

12111221211021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 134555885 (or 134555882 counting only the distinct ones).

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

Adding to 12111221211021 its reverse (12011212211121), we get a palindrome (24122433422142).

The spelling of 12111221211021 in words is "twelve trillion, one hundred eleven billion, two hundred twenty-one million, two hundred eleven thousand, twenty-one".