12210221 has 2 divisors, whose sum is σ = 12210222. Its totient is φ = 12210220.

The previous prime is 12210203. The next prime is 12210223. The reversal of 12210221 is 12201221.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 8934121 + 3276100 = 2989^2 + 1810^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-12210221 is a prime.

Together with 12210223, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12210223) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6105110 + 6105111.

It is an arithmetic number, because the mean of its divisors is an integer number (6105111).

Almost surely, 2^12210221 is an apocalyptic number.

It is an amenable number.

12210221 is a deficient number, since it is larger than the sum of its proper divisors (1).

12210221 is an equidigital number, since it uses as much as digits as its factorization.

12210221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 16, while the sum is 11.

The square root of 12210221 is about 3494.3126648885. The cubic root of 12210221 is about 230.2720221965.

Adding to 12210221 its reverse (12201221), we get a palindrome (24411442).

The spelling of 12210221 in words is "twelve million, two hundred ten thousand, two hundred twenty-one".