12123020121221 has 4 divisors (see below), whose sum is σ = 12129804129792. Its totient is φ = 12116236112652.

The previous prime is 12123020121217. The next prime is 12123020121227. The reversal of 12123020121221 is 12212102032121.

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 12123020121221 - 2² = 12123020121217 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 12123020121193 and 12123020121202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12123020121227) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3392001605 + ... + 3392005178.

It is an arithmetic number, because the mean of its divisors is an integer number (3032451032448).

Almost surely, 2^{12123020121221} is an apocalyptic number.

It is an amenable number.

12123020121221 is a deficient number, since it is larger than the sum of its proper divisors (6784008571).

12123020121221 is an equidigital number, since it uses as much as digits as its factorization.

12123020121221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6784008570.

The product of its (nonzero) digits is 192, while the sum is 20.

Adding to 12123020121221 its reverse (12212102032121), we get a palindrome (24335122153342).

The spelling of 12123020121221 in words is "twelve trillion, one hundred twenty-three billion, twenty million, one hundred twenty-one thousand, two hundred twenty-one".