12222212221 has 4 divisors (see below), whose sum is σ = 12222763744. Its totient is φ = 12221660700.

The previous prime is 12222212173. The next prime is 12222212263. The reversal of 12222212221 is 12221222221.

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 12222212221 - 2⁹ = 12222211709 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 (12222212291) 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, 241065 + ... + 287326.

It is an arithmetic number, because the mean of its divisors is an integer number (3055690936).

Almost surely, 2^12222212221 is an apocalyptic number.

It is an amenable number.

12222212221 is a deficient number, since it is larger than the sum of its proper divisors (551523).

12222212221 is an equidigital number, since it uses as much as digits as its factorization.

12222212221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 551522.

The product of its digits is 256, while the sum is 19.

Adding to 12222212221 its reverse (12221222221), we get a palindrome (24443434442).

The spelling of 12222212221 in words is "twelve billion, two hundred twenty-two million, two hundred twelve thousand, two hundred twenty-one".