91081099 has 2 divisors, whose sum is σ = 91081100. Its totient is φ = 91081098.

The previous prime is 91081097. The next prime is 91081147. The reversal of 91081099 is 99018019.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 91081099 - 2¹ = 91081097 is a prime.

Together with 91081097, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (91081091) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45540549 + 45540550.

It is an arithmetic number, because the mean of its divisors is an integer number (45540550).

Almost surely, 2^91081099 is an apocalyptic number.

91081099 is a deficient number, since it is larger than the sum of its proper divisors (1).

91081099 is an equidigital number, since it uses as much as digits as its factorization.

91081099 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5832, while the sum is 37.

The square root of 91081099 is about 9543.6418101268. The cubic root of 91081099 is about 449.9277233714.

The spelling of 91081099 in words is "ninety-one million, eighty-one thousand, ninety-nine".