9909431321 has 2 divisors, whose sum is σ = 9909431322. Its totient is φ = 9909431320.

The previous prime is 9909431293. The next prime is 9909431339. The reversal of 9909431321 is 1231349099.

9909431321 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., 5589655696 + 4319775625 = 74764^2 + 65725^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-9909431321 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (9909431351) 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, 4954715660 + 4954715661.

It is an arithmetic number, because the mean of its divisors is an integer number (4954715661).

Almost surely, 2^9909431321 is an apocalyptic number.

It is an amenable number.

9909431321 is a deficient number, since it is larger than the sum of its proper divisors (1).

9909431321 is an equidigital number, since it uses as much as digits as its factorization.

9909431321 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 52488, while the sum is 41.

The square root of 9909431321 is about 99546.1265996824. The cubic root of 9909431321 is about 2147.9108114474.

The spelling of 9909431321 in words is "nine billion, nine hundred nine million, four hundred thirty-one thousand, three hundred twenty-one".