21222102120221 has 2 divisors, whose sum is σ = 21222102120222. Its totient is φ = 21222102120220.

The previous prime is 21222102120139. The next prime is 21222102120353. The reversal of 21222102120221 is 12202120122212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14330873356996 + 6891228763225 = 3785614^2 + 2625115^2 .

It is a cyclic number.

It is not a de Polignac number, because 21222102120221 - 2³⁰ = 21221028378397 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21222102120193 and 21222102120202.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21222102120721) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10611051060110 + 10611051060111.

It is an arithmetic number, because the mean of its divisors is an integer number (10611051060111).

Almost surely, 2^{21222102120221} is an apocalyptic number.

It is an amenable number.

21222102120221 is a deficient number, since it is larger than the sum of its proper divisors (1).

21222102120221 is an equidigital number, since it uses as much as digits as its factorization.

21222102120221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 256, while the sum is 20.

Adding to 21222102120221 its reverse (12202120122212), we get a palindrome (33424222242433).

The spelling of 21222102120221 in words is "twenty-one trillion, two hundred twenty-two billion, one hundred two million, one hundred twenty thousand, two hundred twenty-one".