12122110121221 has 4 divisors (see below), whose sum is σ = 12123955478700. Its totient is φ = 12120264763744.

The previous prime is 12122110121213. The next prime is 12122110121257. The reversal of 12122110121221 is 12212101122121.

It is a happy number.

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 8250601332996 + 3871508788225 = 2872386^2 + 1967615^2 .

It is a cyclic number.

It is not a de Polignac number, because 12122110121221 - 2³ = 12122110121213 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 (12122110121621) 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, 922668886 + ... + 922682023.

It is an arithmetic number, because the mean of its divisors is an integer number (3030988869675).

Almost surely, 2^{12122110121221} is an apocalyptic number.

It is an amenable number.

12122110121221 is a deficient number, since it is larger than the sum of its proper divisors (1845357479).

12122110121221 is an equidigital number, since it uses as much as digits as its factorization.

12122110121221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1845357478.

The product of its (nonzero) digits is 64, while the sum is 19.

Adding to 12122110121221 its reverse (12212101122121), we get a palindrome (24334211243342).

The spelling of 12122110121221 in words is "twelve trillion, one hundred twenty-two billion, one hundred ten million, one hundred twenty-one thousand, two hundred twenty-one".