21220000002217 has 2 divisors, whose sum is σ = 21220000002218. Its totient is φ = 21220000002216.

The previous prime is 21220000002211. The next prime is 21220000002241. The reversal of 21220000002217 is 71220000002212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20532462188176 + 687537814041 = 4531276^2 + 829179^2 .

It is a cyclic number.

It is not a de Polignac number, because 21220000002217 - 2³⁹ = 20670244188329 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21220000002194 and 21220000002203.

It is not a weakly prime, because it can be changed into another prime (21220000002211) 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, 10610000001108 + 10610000001109.

It is an arithmetic number, because the mean of its divisors is an integer number (10610000001109).

Almost surely, 2^{21220000002217} is an apocalyptic number.

It is an amenable number.

21220000002217 is a deficient number, since it is larger than the sum of its proper divisors (1).

21220000002217 is an equidigital number, since it uses as much as digits as its factorization.

21220000002217 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 224, while the sum is 19.

Adding to 21220000002217 its reverse (71220000002212), we get a palindrome (92440000004429).

The spelling of 21220000002217 in words is "twenty-one trillion, two hundred twenty billion, two thousand, two hundred seventeen".