12121002021221 has 4 divisors (see below), whose sum is σ = 12121021481772. Its totient is φ = 12120982560672.

The previous prime is 12121002021211. The next prime is 12121002021229. The reversal of 12121002021221 is 12212020012121.

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 3269276236996 + 8851725784225 = 1808114^2 + 2975185^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-12121002021221 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 12121002021221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12121002021229) 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, 8764016 + ... + 10052361.

It is an arithmetic number, because the mean of its divisors is an integer number (3030255370443).

Almost surely, 2^{12121002021221} is an apocalyptic number.

It is an amenable number.

12121002021221 is a deficient number, since it is larger than the sum of its proper divisors (19460551).

12121002021221 is an equidigital number, since it uses as much as digits as its factorization.

12121002021221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19460550.

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 12121002021221 its reverse (12212020012121), we get a palindrome (24333022033342).

The spelling of 12121002021221 in words is "twelve trillion, one hundred twenty-one billion, two million, twenty-one thousand, two hundred twenty-one".