2100221121221 has 2 divisors, whose sum is σ = 2100221121222. Its totient is φ = 2100221121220.

The previous prime is 2100221121211. The next prime is 2100221121223. The reversal of 2100221121221 is 1221211220012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2097242690596 + 2978430625 = 1448186^2 + 54575^2 .

It is a cyclic number.

It is not a de Polignac number, because 2100221121221 - 2¹⁴ = 2100221104837 is a prime.

Together with 2100221121223, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 2100221121221.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2100221121223) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1050110560610 + 1050110560611.

It is an arithmetic number, because the mean of its divisors is an integer number (1050110560611).

Almost surely, 2^{2100221121221} is an apocalyptic number.

It is an amenable number.

2100221121221 is a deficient number, since it is larger than the sum of its proper divisors (1).

2100221121221 is an equidigital number, since it uses as much as digits as its factorization.

2100221121221 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 17.

Adding to 2100221121221 its reverse (1221211220012), we get a palindrome (3321432341233).

The spelling of 2100221121221 in words is "two trillion, one hundred billion, two hundred twenty-one million, one hundred twenty-one thousand, two hundred twenty-one".