12120021212221 has 4 divisors (see below), whose sum is σ = 13052330536252. Its totient is φ = 11187711888192.

The previous prime is 12120021212213. The next prime is 12120021212419. The reversal of 12120021212221 is 12221212002121.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 481620732121 + 11638400480100 = 693989^2 + 3411510^2 .

It is a cyclic number.

It is not a de Polignac number, because 12120021212221 - 2³ = 12120021212213 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12120021212821) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 466154661996 + ... + 466154662021.

It is an arithmetic number, because the mean of its divisors is an integer number (3263082634063).

Almost surely, 2^{12120021212221} is an apocalyptic number.

It is an amenable number.

12120021212221 is a deficient number, since it is larger than the sum of its proper divisors (932309324031).

12120021212221 is an equidigital number, since it uses as much as digits as its factorization.

12120021212221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 932309324030.

The product of its (nonzero) digits is 128, while the sum is 19.

Adding to 12120021212221 its reverse (12221212002121), we get a palindrome (24341233214342).

The spelling of 12120021212221 in words is "twelve trillion, one hundred twenty billion, twenty-one million, two hundred twelve thousand, two hundred twenty-one".