13221431309 has 2 divisors, whose sum is σ = 13221431310. Its totient is φ = 13221431308.

The previous prime is 13221431227. The next prime is 13221431339. The reversal of 13221431309 is 90313412231.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12911776900 + 309654409 = 113630^2 + 17597^2 .

It is a cyclic number.

It is not a de Polignac number, because 13221431309 - 2⁸ = 13221431053 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (13221431339) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6610715654 + 6610715655.

It is an arithmetic number, because the mean of its divisors is an integer number (6610715655).

Almost surely, 2^13221431309 is an apocalyptic number.

It is an amenable number.

13221431309 is a deficient number, since it is larger than the sum of its proper divisors (1).

13221431309 is an equidigital number, since it uses as much as digits as its factorization.

13221431309 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3888, while the sum is 29.

The spelling of 13221431309 in words is "thirteen billion, two hundred twenty-one million, four hundred thirty-one thousand, three hundred nine".