198909 has 16 divisors (see below), whose sum is σ = 302400. Its totient is φ = 129168.

The previous prime is 198901. The next prime is 198929. The reversal of 198909 is 909891.

It is not a de Polignac number, because 198909 - 2³ = 198901 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (198901) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1362 + ... + 1500.

It is an arithmetic number, because the mean of its divisors is an integer number (18900).

2¹⁹⁸⁹⁰⁹ is an apocalyptic number.

It is an amenable number.

198909 is a deficient number, since it is larger than the sum of its proper divisors (103491).

198909 is a wasteful number, since it uses less digits than its factorization.

198909 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 201 (or 195 counting only the distinct ones).

The product of its (nonzero) digits is 5832, while the sum is 36.

The square root of 198909 is about 445.9921523973. The cubic root of 198909 is about 58.3738240420.

The spelling of 198909 in words is "one hundred ninety-eight thousand, nine hundred nine".