12117221 has 2 divisors, whose sum is σ = 12117222. Its totient is φ = 12117220.

The previous prime is 12117121. The next prime is 12117233. The reversal of 12117221 is 12271121.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 6964321 + 5152900 = 2639^2 + 2270^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-12117221 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 12117221.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12117121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6058610 + 6058611.

It is an arithmetic number, because the mean of its divisors is an integer number (6058611).

Almost surely, 2^12117221 is an apocalyptic number.

It is an amenable number.

12117221 is a deficient number, since it is larger than the sum of its proper divisors (1).

12117221 is an equidigital number, since it uses as much as digits as its factorization.

12117221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 56, while the sum is 17.

The square root of 12117221 is about 3480.9798907779. The cubic root of 12117221 is about 229.6859039579.

Adding to 12117221 its reverse (12271121), we get a palindrome (24388342).

The spelling of 12117221 in words is "twelve million, one hundred seventeen thousand, two hundred twenty-one".