21022110221 has 4 divisors (see below), whose sum is σ = 24025268832. Its totient is φ = 18018951612.

The previous prime is 21022110211. The next prime is 21022110233. The reversal of 21022110221 is 12201122012.

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 a cyclic number.

It is not a de Polignac number, because 21022110221 - 2¹⁰ = 21022109197 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21022110196 and 21022110205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21022110211) 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, 1501579295 + ... + 1501579308.

It is an arithmetic number, because the mean of its divisors is an integer number (6006317208).

Almost surely, 2^21022110221 is an apocalyptic number.

It is an amenable number.

21022110221 is a deficient number, since it is larger than the sum of its proper divisors (3003158611).

21022110221 is an equidigital number, since it uses as much as digits as its factorization.

21022110221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3003158610.

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 21022110221 its reverse (12201122012), we get a palindrome (33223232233).

The spelling of 21022110221 in words is "twenty-one billion, twenty-two million, one hundred ten thousand, two hundred twenty-one".