21201022210221 has 40 divisors (see below), whose sum is σ = 36203179408704. Its totient is φ = 12112146561600.

The previous prime is 21201022210187. The next prime is 21201022210253. The reversal of 21201022210221 is 12201222010212.

It is a happy number.

21201022210221 is a `hidden beast` number, since 2 + 120 + 102 + 221 + 0 + 221 = 666.

It is not a de Polignac number, because 21201022210221 - 2¹¹ = 21201022208173 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21201022210194 and 21201022210203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21201022210021) 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 in 39 ways as a sum of consecutive naturals, for example, 1676640 + ... + 6724073.

Almost surely, 2^{21201022210221} is an apocalyptic number.

21201022210221 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

21201022210221 is a deficient number, since it is larger than the sum of its proper divisors (15002157198483).

21201022210221 is an equidigital number, since it uses as much as digits as its factorization.

21201022210221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8405183 (or 8405174 counting only the distinct ones).

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

Adding to 21201022210221 its reverse (12201222010212), we get a palindrome (33402244220433).

The spelling of 21201022210221 in words is "twenty-one trillion, two hundred one billion, twenty-two million, two hundred ten thousand, two hundred twenty-one".