12351221 has 2 divisors, whose sum is σ = 12351222. Its totient is φ = 12351220.

The previous prime is 12351217. The next prime is 12351223. The reversal of 12351221 is 12215321.

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., 12348196 + 3025 = 3514^2 + 55^2 .

It is an emirp because it is prime and its reverse (12215321) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 12351221 - 2² = 12351217 is a prime.

Together with 12351223, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 12351221.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12351223) by changing a digit.

It is a good prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6175610 + 6175611.

It is an arithmetic number, because the mean of its divisors is an integer number (6175611).

Almost surely, 2^12351221 is an apocalyptic number.

It is an amenable number.

12351221 is a deficient number, since it is larger than the sum of its proper divisors (1).

12351221 is an equidigital number, since it uses as much as digits as its factorization.

12351221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 120, while the sum is 17.

The square root of 12351221 is about 3514.4303948151. The cubic root of 12351221 is about 231.1550030066.

Adding to 12351221 its reverse (12215321), we get a palindrome (24566542).

The spelling of 12351221 in words is "twelve million, three hundred fifty-one thousand, two hundred twenty-one".