198209901091 has 4 divisors (see below), whose sum is σ = 201569391000. Its totient is φ = 194850411184.

The previous prime is 198209901059. The next prime is 198209901107. The reversal of 198209901091 is 190109902891.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 198209901091 - 2⁵ = 198209901059 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (198209901011) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1679744866 + ... + 1679744983.

It is an arithmetic number, because the mean of its divisors is an integer number (50392347750).

Almost surely, 2^198209901091 is an apocalyptic number.

198209901091 is a deficient number, since it is larger than the sum of its proper divisors (3359489909).

198209901091 is an equidigital number, since it uses as much as digits as its factorization.

198209901091 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3359489908.

The product of its (nonzero) digits is 104976, while the sum is 49.

The spelling of 198209901091 in words is "one hundred ninety-eight billion, two hundred nine million, nine hundred one thousand, ninety-one".