9901000091 has 2 divisors, whose sum is σ = 9901000092. Its totient is φ = 9901000090.

The previous prime is 9901000063. The next prime is 9901000093. The reversal of 9901000091 is 1900001099.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 9901000091 - 2¹⁰ = 9900999067 is a prime.

Together with 9901000093, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (9901000093) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4950500045 + 4950500046.

It is an arithmetic number, because the mean of its divisors is an integer number (4950500046).

Almost surely, 2^9901000091 is an apocalyptic number.

9901000091 is a deficient number, since it is larger than the sum of its proper divisors (1).

9901000091 is an equidigital number, since it uses as much as digits as its factorization.

9901000091 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 729, while the sum is 29.

The square root of 9901000091 is about 99503.7692301151. The cubic root of 9901000091 is about 2147.3014704419.

The spelling of 9901000091 in words is "nine billion, nine hundred one million, ninety-one", and thus it is an aban number.