12112212121221 has 4 divisors (see below), whose sum is σ = 16149616161632. Its totient is φ = 8074808080812.

The previous prime is 12112212121187. The next prime is 12112212121223. The reversal of 12112212121221 is 12212121221121.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 12112212121221 - 2¹⁷ = 12112211990149 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12112212121223) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2018702020201 + ... + 2018702020206.

It is an arithmetic number, because the mean of its divisors is an integer number (4037404040408).

Almost surely, 2^{12112212121221} is an apocalyptic number.

It is an amenable number.

12112212121221 is a deficient number, since it is larger than the sum of its proper divisors (4037404040411).

12112212121221 is an equidigital number, since it uses as much as digits as its factorization.

12112212121221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4037404040410.

The product of its digits is 128, while the sum is 21.

Adding to 12112212121221 its reverse (12212121221121), we get a palindrome (24324333342342).

It can be divided in two parts, 121 and 12212121221, that multiplied together give a palindrome (1477666667741).

The spelling of 12112212121221 in words is "twelve trillion, one hundred twelve billion, two hundred twelve million, one hundred twenty-one thousand, two hundred twenty-one".