21202222120221 has 4 divisors (see below), whose sum is σ = 28269629493632. Its totient is φ = 14134814746812.

The previous prime is 21202222120217. The next prime is 21202222120237. The reversal of 21202222120221 is 12202122220212.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 21202222120221 - 2² = 21202222120217 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21202222120421) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3533703686701 + ... + 3533703686706.

It is an arithmetic number, because the mean of its divisors is an integer number (7067407373408).

Almost surely, 2^{21202222120221} is an apocalyptic number.

It is an amenable number.

21202222120221 is a deficient number, since it is larger than the sum of its proper divisors (7067407373411).

21202222120221 is an equidigital number, since it uses as much as digits as its factorization.

21202222120221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7067407373410.

The product of its (nonzero) digits is 512, while the sum is 21.

Adding to 21202222120221 its reverse (12202122220212), we get a palindrome (33404344340433).

Subtracting from 21202222120221 its reverse (12202122220212), we obtain a palindrome (9000099900009).

The spelling of 21202222120221 in words is "twenty-one trillion, two hundred two billion, two hundred twenty-two million, one hundred twenty thousand, two hundred twenty-one".