91099871 has 2 divisors, whose sum is σ = 91099872. Its totient is φ = 91099870.

The previous prime is 91099861. The next prime is 91099873. The reversal of 91099871 is 17899019.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 91099871 - 2⁶ = 91099807 is a prime.

Together with 91099873, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (91099873) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45549935 + 45549936.

It is an arithmetic number, because the mean of its divisors is an integer number (45549936).

Almost surely, 2^91099871 is an apocalyptic number.

91099871 is a deficient number, since it is larger than the sum of its proper divisors (1).

91099871 is an equidigital number, since it uses as much as digits as its factorization.

91099871 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 40824, while the sum is 44.

The square root of 91099871 is about 9544.6252414644. The cubic root of 91099871 is about 449.9586315881.

The spelling of 91099871 in words is "ninety-one million, ninety-nine thousand, eight hundred seventy-one".