21210210222217 has 2 divisors, whose sum is σ = 21210210222218. Its totient is φ = 21210210222216.

The previous prime is 21210210222211. The next prime is 21210210222293. The reversal of 21210210222217 is 71222201201212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21164269015296 + 45941206921 = 4600464^2 + 214339^2 .

It is a cyclic number.

It is not a de Polignac number, because 21210210222217 - 2²³ = 21210201833609 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21210210222191 and 21210210222200.

It is not a weakly prime, because it can be changed into another prime (21210210222211) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10605105111108 + 10605105111109.

It is an arithmetic number, because the mean of its divisors is an integer number (10605105111109).

Almost surely, 2^{21210210222217} is an apocalyptic number.

It is an amenable number.

21210210222217 is a deficient number, since it is larger than the sum of its proper divisors (1).

21210210222217 is an equidigital number, since it uses as much as digits as its factorization.

21210210222217 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 896, while the sum is 25.

Adding to 21210210222217 its reverse (71222201201212), we get a palindrome (92432411423429).

The spelling of 21210210222217 in words is "twenty-one trillion, two hundred ten billion, two hundred ten million, two hundred twenty-two thousand, two hundred seventeen".