12122121111221 has 12 divisors (see below), whose sum is σ = 13783774080300. Its totient is φ = 10640106301440.

The previous prime is 12122121111211. The next prime is 12122121111229. The reversal of 12122121111221 is 12211112122121.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 5263876730596 + 6858244380625 = 2294314^2 + 2618825^2 .

It is not a de Polignac number, because 12122121111221 - 2¹⁸ = 12122120849077 is a prime.

It is a super-2 number, since 2×12122121111221² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 12122121111193 and 12122121111202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12122121111229) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1727286476 + ... + 1727293493.

It is an arithmetic number, because the mean of its divisors is an integer number (1148647840025).

Almost surely, 2^{12122121111221} is an apocalyptic number.

12122121111221 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

12122121111221 is a deficient number, since it is larger than the sum of its proper divisors (1661652969079).

12122121111221 is a wasteful number, since it uses less digits than its factorization.

12122121111221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3454580020 (or 3454580009 counting only the distinct ones).

The product of its digits is 64, while the sum is 20.

Adding to 12122121111221 its reverse (12211112122121), we get a palindrome (24333233233342).

The spelling of 12122121111221 in words is "twelve trillion, one hundred twenty-two billion, one hundred twenty-one million, one hundred eleven thousand, two hundred twenty-one".