21220202221 has 8 divisors (see below), whose sum is σ = 21489773760. Its totient is φ = 20950961952.

The previous prime is 21220202203. The next prime is 21220202233. The reversal of 21220202221 is 12220202212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21220202221 - 2⁵ = 21220202189 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21220202195 and 21220202204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21220202251) 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 7 ways as a sum of consecutive naturals, for example, 47401 + ... + 211393.

It is an arithmetic number, because the mean of its divisors is an integer number (2686221720).

Almost surely, 2^21220202221 is an apocalyptic number.

It is an amenable number.

21220202221 is a deficient number, since it is larger than the sum of its proper divisors (269571539).

21220202221 is a wasteful number, since it uses less digits than its factorization.

21220202221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 165635.

The product of its (nonzero) digits is 128, while the sum is 16.

Adding to 21220202221 its reverse (12220202212), we get a palindrome (33440404433).

Subtracting from 21220202221 its reverse (12220202212), we obtain a palindrome (9000000009).

The spelling of 21220202221 in words is "twenty-one billion, two hundred twenty million, two hundred two thousand, two hundred twenty-one".