21202220221321 has 2 divisors, whose sum is σ = 21202220221322. Its totient is φ = 21202220221320.

The previous prime is 21202220221249. The next prime is 21202220221337. The reversal of 21202220221321 is 12312202220212.

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., 11562964990096 + 9639255231225 = 3400436^2 + 3104715^2 .

It is a cyclic number.

It is not a de Polignac number, because 21202220221321 - 2¹¹ = 21202220219273 is a prime.

It is a super-2 number, since 2×21202220221321² (a number of 27 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21202220221292 and 21202220221301.

It is not a weakly prime, because it can be changed into another prime (21202220225321) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10601110110660 + 10601110110661.

It is an arithmetic number, because the mean of its divisors is an integer number (10601110110661).

Almost surely, 2^{21202220221321} is an apocalyptic number.

It is an amenable number.

21202220221321 is a deficient number, since it is larger than the sum of its proper divisors (1).

21202220221321 is an equidigital number, since it uses as much as digits as its factorization.

21202220221321 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 768, while the sum is 22.

Adding to 21202220221321 its reverse (12312202220212), we get a palindrome (33514422441533).

The spelling of 21202220221321 in words is "twenty-one trillion, two hundred two billion, two hundred twenty million, two hundred twenty-one thousand, three hundred twenty-one".