12432221 has 2 divisors, whose sum is σ = 12432222. Its totient is φ = 12432220.

The previous prime is 12432193. The next prime is 12432241. The reversal of 12432221 is 12223421.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 9369721 + 3062500 = 3061^2 + 1750^2 .

It is a cyclic number.

It is not a de Polignac number, because 12432221 - 2¹⁰ = 12431197 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 12432221.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12432241) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6216110 + 6216111.

It is an arithmetic number, because the mean of its divisors is an integer number (6216111).

Almost surely, 2^12432221 is an apocalyptic number.

It is an amenable number.

12432221 is a deficient number, since it is larger than the sum of its proper divisors (1).

12432221 is an equidigital number, since it uses as much as digits as its factorization.

12432221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 192, while the sum is 17.

The square root of 12432221 is about 3525.9354787063. The cubic root of 12432221 is about 231.6592115561.

Adding to 12432221 its reverse (12223421), we get a palindrome (24655642).

It can be divided in two parts, 12432 and 221, that multiplied together give a palindrome (2747472).

The spelling of 12432221 in words is "twelve million, four hundred thirty-two thousand, two hundred twenty-one".