21222011200021 has 2 divisors, whose sum is σ = 21222011200022. Its totient is φ = 21222011200020.

The previous prime is 21222011200009. The next prime is 21222011200087. The reversal of 21222011200021 is 12000211022212.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13389927600625 + 7832083599396 = 3659225^2 + 2798586^2 .

It is a cyclic number.

It is not a de Polignac number, because 21222011200021 - 2³⁵ = 21187651461653 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21222011199968 and 21222011200004.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21222011200121) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10611005600010 + 10611005600011.

It is an arithmetic number, because the mean of its divisors is an integer number (10611005600011).

Almost surely, 2^{21222011200021} is an apocalyptic number.

It is an amenable number.

21222011200021 is a deficient number, since it is larger than the sum of its proper divisors (1).

21222011200021 is an equidigital number, since it uses as much as digits as its factorization.

21222011200021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 21222011200021 its reverse (12000211022212), we get a palindrome (33222222222233).

The spelling of 21222011200021 in words is "twenty-one trillion, two hundred twenty-two billion, eleven million, two hundred thousand, twenty-one".