10009991909 has 2 divisors, whose sum is σ = 10009991910. Its totient is φ = 10009991908.

The previous prime is 10009991879. The next prime is 10009991917. The reversal of 10009991909 is 90919990001.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 7340719684 + 2669272225 = 85678^2 + 51665^2 .

It is a cyclic number.

It is not a de Polignac number, because 10009991909 - 2²⁸ = 9741556453 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (10009991609) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5004995954 + 5004995955.

It is an arithmetic number, because the mean of its divisors is an integer number (5004995955).

Almost surely, 2^10009991909 is an apocalyptic number.

It is an amenable number.

10009991909 is a deficient number, since it is larger than the sum of its proper divisors (1).

10009991909 is an equidigital number, since it uses as much as digits as its factorization.

10009991909 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 59049, while the sum is 47.

The spelling of 10009991909 in words is "ten billion, nine million, nine hundred ninety-one thousand, nine hundred nine".