21201122212217 has 2 divisors, whose sum is σ = 21201122212218. Its totient is φ = 21201122212216.

The previous prime is 21201122212183. The next prime is 21201122212219. The reversal of 21201122212217 is 71221222110212.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21198114347881 + 3007864336 = 4604141^2 + 54844^2 .

It is a cyclic number.

It is not a de Polignac number, because 21201122212217 - 2⁸ = 21201122211961 is a prime.

It is a super-3 number, since 3×21201122212217³ (a number of 41 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

Together with 21201122212219, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21201122212219) 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 as a sum of consecutive naturals, namely, 10600561106108 + 10600561106109.

It is an arithmetic number, because the mean of its divisors is an integer number (10600561106109).

Almost surely, 2^{21201122212217} is an apocalyptic number.

It is an amenable number.

21201122212217 is a deficient number, since it is larger than the sum of its proper divisors (1).

21201122212217 is an equidigital number, since it uses as much as digits as its factorization.

21201122212217 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 896, while the sum is 26.

Adding to 21201122212217 its reverse (71221222110212), we get a palindrome (92422344322429).

The spelling of 21201122212217 in words is "twenty-one trillion, two hundred one billion, one hundred twenty-two million, two hundred twelve thousand, two hundred seventeen".