13212223331221 has 2 divisors, whose sum is σ = 13212223331222. Its totient is φ = 13212223331220.

The previous prime is 13212223331191. The next prime is 13212223331227. The reversal of 13212223331221 is 12213332221231.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 9923854546225 + 3288368784996 = 3150215^2 + 1813386^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-13212223331221 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 13212223331221.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (13212223331227) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6606111665610 + 6606111665611.

It is an arithmetic number, because the mean of its divisors is an integer number (6606111665611).

Almost surely, 2^{13212223331221} is an apocalyptic number.

It is an amenable number.

13212223331221 is a deficient number, since it is larger than the sum of its proper divisors (1).

13212223331221 is an equidigital number, since it uses as much as digits as its factorization.

13212223331221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5184, while the sum is 28.

Adding to 13212223331221 its reverse (12213332221231), we get a palindrome (25425555552452).

The spelling of 13212223331221 in words is "thirteen trillion, two hundred twelve billion, two hundred twenty-three million, three hundred thirty-one thousand, two hundred twenty-one".