9917904209 has 2 divisors, whose sum is σ = 9917904210. Its totient is φ = 9917904208.

The previous prime is 9917904197. The next prime is 9917904247. The reversal of 9917904209 is 9024097199.

9917904209 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 8231569984 + 1686334225 = 90728^2 + 41065^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-9917904209 is a prime.

It is not a weakly prime, because it can be changed into another prime (9917904289) 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, 4958952104 + 4958952105.

It is an arithmetic number, because the mean of its divisors is an integer number (4958952105).

Almost surely, 2^9917904209 is an apocalyptic number.

It is an amenable number.

9917904209 is a deficient number, since it is larger than the sum of its proper divisors (1).

9917904209 is an equidigital number, since it uses as much as digits as its factorization.

9917904209 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 367416, while the sum is 50.

The square root of 9917904209 is about 99588.6751041503. The cubic root of 9917904209 is about 2148.5228150595.

The spelling of 9917904209 in words is "nine billion, nine hundred seventeen million, nine hundred four thousand, two hundred nine".