22221201221 has 4 divisors (see below), whose sum is σ = 22221599712. Its totient is φ = 22220802732.

The previous prime is 22221201217. The next prime is 22221201227. The reversal of 22221201221 is 12210212222.

It is a happy number.

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 22221201221 - 2² = 22221201217 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 22221201221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (22221201227) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 98681 + ... + 232766.

It is an arithmetic number, because the mean of its divisors is an integer number (5555399928).

Almost surely, 2^22221201221 is an apocalyptic number.

It is an amenable number.

22221201221 is a deficient number, since it is larger than the sum of its proper divisors (398491).

22221201221 is an equidigital number, since it uses as much as digits as its factorization.

22221201221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 398490.

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

Adding to 22221201221 its reverse (12210212222), we get a palindrome (34431413443).

The spelling of 22221201221 in words is "twenty-two billion, two hundred twenty-one million, two hundred one thousand, two hundred twenty-one".