198209191 has 4 divisors (see below), whose sum is σ = 201458584. Its totient is φ = 194959800.

The previous prime is 198209189. The next prime is 198209201. The reversal of 198209191 is 191902891.

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 198209191 - 2¹ = 198209189 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (198209131) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1624605 + ... + 1624726.

It is an arithmetic number, because the mean of its divisors is an integer number (50364646).

Almost surely, 2^198209191 is an apocalyptic number.

198209191 is a deficient number, since it is larger than the sum of its proper divisors (3249393).

198209191 is an equidigital number, since it uses as much as digits as its factorization.

198209191 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3249392.

The product of its (nonzero) digits is 11664, while the sum is 40.

The square root of 198209191 is about 14078.6785956637. The cubic root of 198209191 is about 583.0528595246.

The spelling of 198209191 in words is "one hundred ninety-eight million, two hundred nine thousand, one hundred ninety-one".