21202122120217 has 2 divisors, whose sum is σ = 21202122120218. Its totient is φ = 21202122120216.

The previous prime is 21202122120149. The next prime is 21202122120229. The reversal of 21202122120217 is 71202122120212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18665951208921 + 2536170911296 = 4320411^2 + 1592536^2 .

It is a cyclic number.

It is not a de Polignac number, because 21202122120217 - 2¹⁵ = 21202122087449 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21202122120191 and 21202122120200.

It is not a weakly prime, because it can be changed into another prime (21202122120917) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10601061060108 + 10601061060109.

It is an arithmetic number, because the mean of its divisors is an integer number (10601061060109).

Almost surely, 2^{21202122120217} is an apocalyptic number.

It is an amenable number.

21202122120217 is a deficient number, since it is larger than the sum of its proper divisors (1).

21202122120217 is an equidigital number, since it uses as much as digits as its factorization.

21202122120217 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 21202122120217 its reverse (71202122120212), we get a palindrome (92404244240429).

The spelling of 21202122120217 in words is "twenty-one trillion, two hundred two billion, one hundred twenty-two million, one hundred twenty thousand, two hundred seventeen".