198085091 has 2 divisors, whose sum is σ = 198085092. Its totient is φ = 198085090.

The previous prime is 198085081. The next prime is 198085093. The reversal of 198085091 is 190580891.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 198085091 - 2²² = 193890787 is a prime.

It is a Sophie Germain prime.

Together with 198085093, 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 (198085093) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99042545 + 99042546.

It is an arithmetic number, because the mean of its divisors is an integer number (99042546).

Almost surely, 2^198085091 is an apocalyptic number.

198085091 is a deficient number, since it is larger than the sum of its proper divisors (1).

198085091 is an equidigital number, since it uses as much as digits as its factorization.

198085091 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 25920, while the sum is 41.

The square root of 198085091 is about 14074.2705317185. The cubic root of 198085091 is about 582.9311497866.

The spelling of 198085091 in words is "one hundred ninety-eight million, eighty-five thousand, ninety-one".