13311231221 has 2 divisors, whose sum is σ = 13311231222. Its totient is φ = 13311231220.

The previous prime is 13311231203. The next prime is 13311231229. The reversal of 13311231221 is 12213211331.

It is a happy number.

13311231221 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 10178590321 + 3132640900 = 100889^2 + 55970^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-13311231221 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 13311231193 and 13311231202.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (13311231229) 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, 6655615610 + 6655615611.

It is an arithmetic number, because the mean of its divisors is an integer number (6655615611).

Almost surely, 2^13311231221 is an apocalyptic number.

It is an amenable number.

13311231221 is a deficient number, since it is larger than the sum of its proper divisors (1).

13311231221 is an equidigital number, since it uses as much as digits as its factorization.

13311231221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 216, while the sum is 20.

Adding to 13311231221 its reverse (12213211331), we get a palindrome (25524442552).

The spelling of 13311231221 in words is "thirteen billion, three hundred eleven million, two hundred thirty-one thousand, two hundred twenty-one".