12121212011221 has 2 divisors, whose sum is σ = 12121212011222. Its totient is φ = 12121212011220.

The previous prime is 12121212011219. The next prime is 12121212011269. The reversal of 12121212011221 is 12211021212121.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 9135590880196 + 2985621131025 = 3022514^2 + 1727895^2 .

It is a cyclic number.

It is not a de Polignac number, because 12121212011221 - 2¹ = 12121212011219 is a prime.

Together with 12121212011219, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12121212011921) 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 as a sum of consecutive naturals, namely, 6060606005610 + 6060606005611.

It is an arithmetic number, because the mean of its divisors is an integer number (6060606005611).

Almost surely, 2^{12121212011221} is an apocalyptic number.

It is an amenable number.

12121212011221 is a deficient number, since it is larger than the sum of its proper divisors (1).

12121212011221 is an equidigital number, since it uses as much as digits as its factorization.

12121212011221 is an odious number, because the sum of its binary digits is odd.

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

Adding to 12121212011221 its reverse (12211021212121), we get a palindrome (24332233223342).

The spelling of 12121212011221 in words is "twelve trillion, one hundred twenty-one billion, two hundred twelve million, eleven thousand, two hundred twenty-one".