12312221 has 2 divisors, whose sum is σ = 12312222. Its totient is φ = 12312220.

The previous prime is 12312217. The next prime is 12312227. The reversal of 12312221 is 12221321.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 6604900 + 5707321 = 2570^2 + 2389^2 .

It is a cyclic number.

It is not a de Polignac number, because 12312221 - 2² = 12312217 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 12312196 and 12312205.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12312227) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6156110 + 6156111.

It is an arithmetic number, because the mean of its divisors is an integer number (6156111).

Almost surely, 2^12312221 is an apocalyptic number.

It is an amenable number.

12312221 is a deficient number, since it is larger than the sum of its proper divisors (1).

12312221 is an equidigital number, since it uses as much as digits as its factorization.

12312221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 48, while the sum is 14.

The square root of 12312221 is about 3508.8774558254. The cubic root of 12312221 is about 230.9114494777.

Adding to 12312221 its reverse (12221321), we get a palindrome (24533542).

The spelling of 12312221 in words is "twelve million, three hundred twelve thousand, two hundred twenty-one".