21002221210221 has 64 divisors (see below), whose sum is σ = 31306151116800. Its totient is φ = 13915555227072.

The previous prime is 21002221210193. The next prime is 21002221210247. The reversal of 21002221210221 is 12201212220012.

It is a happy number.

21002221210221 is a `hidden beast` number, since 2 + 10 + 0 + 2 + 221 + 210 + 221 = 666.

It is not a de Polignac number, because 21002221210221 - 2¹¹ = 21002221208173 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21002221210194 and 21002221210203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21002221210721) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 3402268291 + ... + 3402274463.

It is an arithmetic number, because the mean of its divisors is an integer number (489158611200).

Almost surely, 2^{21002221210221} is an apocalyptic number.

It is an amenable number.

21002221210221 is a deficient number, since it is larger than the sum of its proper divisors (10303929906579).

21002221210221 is a wasteful number, since it uses less digits than its factorization.

21002221210221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7687 (or 7681 counting only the distinct ones).

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

Adding to 21002221210221 its reverse (12201212220012), we get a palindrome (33203433430233).

The spelling of 21002221210221 in words is "twenty-one trillion, two billion, two hundred twenty-one million, two hundred ten thousand, two hundred twenty-one".