21222011220021 has 6 divisors (see below), whose sum is σ = 30654016206710. Its totient is φ = 14148007480008.

The previous prime is 21222011220017. The next prime is 21222011220089. The reversal of 21222011220021 is 12002211022212.

It is a happy number.

21222011220021 is a `hidden beast` number, since 212 + 220 + 1 + 12 + 200 + 21 = 666.

It can be written as a sum of positive squares in only one way, i.e., 21155078286225 + 66932933796 = 4599465^2 + 258714^2 .

It is not a de Polignac number, because 21222011220021 - 2² = 21222011220017 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21222011219976 and 21222011220003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21222011220521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1179000623326 + ... + 1179000623343.

Almost surely, 2^{21222011220021} is an apocalyptic number.

It is an amenable number.

21222011220021 is a deficient number, since it is larger than the sum of its proper divisors (9432004986689).

21222011220021 is a wasteful number, since it uses less digits than its factorization.

21222011220021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2358001246675 (or 2358001246672 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

Adding to 21222011220021 its reverse (12002211022212), we get a palindrome (33224222242233).

The spelling of 21222011220021 in words is "twenty-one trillion, two hundred twenty-two billion, eleven million, two hundred twenty thousand, twenty-one".