21220202022221 has 24 divisors (see below), whose sum is σ = 22909705301952. Its totient is φ = 19606448048000.

The previous prime is 21220202022211. The next prime is 21220202022233. The reversal of 21220202022221 is 12222020202212.

It is not a de Polignac number, because 21220202022221 - 2¹⁰ = 21220202021197 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21220202022193 and 21220202022202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21220202022211) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 8516570 + ... + 10722516.

It is an arithmetic number, because the mean of its divisors is an integer number (954571054248).

Almost surely, 2^{21220202022221} is an apocalyptic number.

It is an amenable number.

21220202022221 is a deficient number, since it is larger than the sum of its proper divisors (1689503279731).

21220202022221 is a wasteful number, since it uses less digits than its factorization.

21220202022221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2206213 (or 2206112 counting only the distinct ones).

The product of its (nonzero) digits is 512, while the sum is 20.

Adding to 21220202022221 its reverse (12222020202212), we get a palindrome (33442222224433).

The spelling of 21220202022221 in words is "twenty-one trillion, two hundred twenty billion, two hundred two million, twenty-two thousand, two hundred twenty-one".