9991000099 has 2 divisors, whose sum is σ = 9991000100. Its totient is φ = 9991000098.

The previous prime is 9991000087. The next prime is 9991000133. The reversal of 9991000099 is 9900001999.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 9991000099 - 2⁷ = 9990999971 is a prime.

It is not a weakly prime, because it can be changed into another prime (9991000039) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4995500049 + 4995500050.

It is an arithmetic number, because the mean of its divisors is an integer number (4995500050).

Almost surely, 2^9991000099 is an apocalyptic number.

9991000099 is a deficient number, since it is larger than the sum of its proper divisors (1).

9991000099 is an equidigital number, since it uses as much as digits as its factorization.

9991000099 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 46.

The square root of 9991000099 is about 99954.9903656641. The cubic root of 9991000099 is about 2153.7881727426.

The spelling of 9991000099 in words is "nine billion, nine hundred ninety-one million, ninety-nine", and thus it is an aban number.