12220221221 has 4 divisors (see below), whose sum is σ = 13160238252. Its totient is φ = 11280204192.

The previous prime is 12220221217. The next prime is 12220221239. The reversal of 12220221221 is 12212202221.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12212202221 = 18517 ⋅659513.

It can be written as a sum of positive squares in 2 ways, for example, as 2762658721 + 9457562500 = 52561^2 + 97250^2 .

It is a cyclic number.

It is not a de Polignac number, because 12220221221 - 2² = 12220221217 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 12220221221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12220221121) 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, 470008496 + ... + 470008521.

It is an arithmetic number, because the mean of its divisors is an integer number (3290059563).

Almost surely, 2^12220221221 is an apocalyptic number.

It is an amenable number.

12220221221 is a deficient number, since it is larger than the sum of its proper divisors (940017031).

12220221221 is an equidigital number, since it uses as much as digits as its factorization.

12220221221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 940017030.

The product of its (nonzero) digits is 128, while the sum is 17.

Adding to 12220221221 its reverse (12212202221), we get a palindrome (24432423442).

The spelling of 12220221221 in words is "twelve billion, two hundred twenty million, two hundred twenty-one thousand, two hundred twenty-one".