22212721221 has 4 divisors (see below), whose sum is σ = 29616961632. Its totient is φ = 14808480812.

The previous prime is 22212721217. The next prime is 22212721243. The reversal of 22212721221 is 12212721222.

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 22212721221 - 2² = 22212721217 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 22212721191 and 22212721200.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (22212721211) 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, 3702120201 + ... + 3702120206.

It is an arithmetic number, because the mean of its divisors is an integer number (7404240408).

Almost surely, 2^22212721221 is an apocalyptic number.

It is an amenable number.

22212721221 is a deficient number, since it is larger than the sum of its proper divisors (7404240411).

22212721221 is an equidigital number, since it uses as much as digits as its factorization.

22212721221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7404240410.

The product of its digits is 896, while the sum is 24.

Subtracting from 22212721221 its reverse (12212721222), we obtain a palindrome (9999999999).

The spelling of 22212721221 in words is "twenty-two billion, two hundred twelve million, seven hundred twenty-one thousand, two hundred twenty-one".