12121202021221 has 4 divisors (see below), whose sum is σ = 12208404913600. Its totient is φ = 12033999128844.

The previous prime is 12121202021191. The next prime is 12121202021323. The reversal of 12121202021221 is 12212020212121.

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 a cyclic number.

It is not a de Polignac number, because 12121202021221 - 2⁵ = 12121202021189 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 (12121202021821) 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, 43601445981 + ... + 43601446258.

It is an arithmetic number, because the mean of its divisors is an integer number (3052101228400).

Almost surely, 2^{12121202021221} is an apocalyptic number.

It is an amenable number.

12121202021221 is a deficient number, since it is larger than the sum of its proper divisors (87202892379).

12121202021221 is an equidigital number, since it uses as much as digits as its factorization.

12121202021221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 87202892378.

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

Adding to 12121202021221 its reverse (12212020212121), we get a palindrome (24333222233342).

The spelling of 12121202021221 in words is "twelve trillion, one hundred twenty-one billion, two hundred two million, twenty-one thousand, two hundred twenty-one".