22221021221 has 12 divisors (see below), whose sum is σ = 26115432588. Its totient is φ = 18850228992.

The previous prime is 22221021191. The next prime is 22221021233. The reversal of 22221021221 is 12212012222.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 13337016196 + 8884005025 = 115486^2 + 94255^2 .

It is a de Polignac number, because none of the positive numbers 2^k-22221021221 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 22221021221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (22221021821) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2332826 + ... + 2342331.

It is an arithmetic number, because the mean of its divisors is an integer number (2176286049).

Almost surely, 2^22221021221 is an apocalyptic number.

It is an amenable number.

22221021221 is a deficient number, since it is larger than the sum of its proper divisors (3894411367).

22221021221 is an equidigital number, since it uses as much as digits as its factorization.

22221021221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4675268 (or 4675261 counting only the distinct ones).

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

Adding to 22221021221 its reverse (12212012222), we get a palindrome (34433033443).

The spelling of 22221021221 in words is "twenty-two billion, two hundred twenty-one million, twenty-one thousand, two hundred twenty-one".