21031322021221 has 2 divisors, whose sum is σ = 21031322021222. Its totient is φ = 21031322021220.

The previous prime is 21031322021207. The next prime is 21031322021263. The reversal of 21031322021221 is 12212022313012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16188439592196 + 4842882429025 = 4023486^2 + 2200655^2 .

It is a cyclic number.

It is not a de Polignac number, because 21031322021221 - 2¹¹ = 21031322019173 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21031322021192 and 21031322021201.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21031322024221) 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, 10515661010610 + 10515661010611.

It is an arithmetic number, because the mean of its divisors is an integer number (10515661010611).

Almost surely, 2^{21031322021221} is an apocalyptic number.

It is an amenable number.

21031322021221 is a deficient number, since it is larger than the sum of its proper divisors (1).

21031322021221 is an equidigital number, since it uses as much as digits as its factorization.

21031322021221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 576, while the sum is 22.

Adding to 21031322021221 its reverse (12212022313012), we get a palindrome (33243344334233).

The spelling of 21031322021221 in words is "twenty-one trillion, thirty-one billion, three hundred twenty-two million, twenty-one thousand, two hundred twenty-one".