21220001202217 has 2 divisors, whose sum is σ = 21220001202218. Its totient is φ = 21220001202216.

The previous prime is 21220001202173. The next prime is 21220001202271. The reversal of 21220001202217 is 71220210002212.

Together with next prime (21220001202271) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16337408305936 + 4882592896281 = 4041956^2 + 2209659^2 .

It is a cyclic number.

It is not a de Polignac number, because 21220001202217 - 2¹⁹ = 21220000677929 is a prime.

It is not a weakly prime, because it can be changed into another prime (21220001205217) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10610000601108 + 10610000601109.

It is an arithmetic number, because the mean of its divisors is an integer number (10610000601109).

Almost surely, 2^{21220001202217} is an apocalyptic number.

It is an amenable number.

21220001202217 is a deficient number, since it is larger than the sum of its proper divisors (1).

21220001202217 is an equidigital number, since it uses as much as digits as its factorization.

21220001202217 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 448, while the sum is 22.

Adding to 21220001202217 its reverse (71220210002212), we get a palindrome (92440211204429).

The spelling of 21220001202217 in words is "twenty-one trillion, two hundred twenty billion, one million, two hundred two thousand, two hundred seventeen".