198091 has 2 divisors, whose sum is σ = 198092. Its totient is φ = 198090.

The previous prime is 198083. The next prime is 198097. The reversal of 198091 is 190891.

198091 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is an emirp because it is prime and its reverse (190891) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 198091 - 2³ = 198083 is a prime.

It is an Ulam number.

It is not a weakly prime, because it can be changed into another prime (198097) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99045 + 99046.

It is an arithmetic number, because the mean of its divisors is an integer number (99046).

2¹⁹⁸⁰⁹¹ is an apocalyptic number.

198091 is a deficient number, since it is larger than the sum of its proper divisors (1).

198091 is an equidigital number, since it uses as much as digits as its factorization.

198091 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 648, while the sum is 28.

The square root of 198091 is about 445.0741511254. The cubic root of 198091 is about 58.2936946127.

The spelling of 198091 in words is "one hundred ninety-eight thousand, ninety-one".