198009 has 18 divisors (see below), whose sum is σ = 333450. Its totient is φ = 112896.

The previous prime is 197971. The next prime is 198013. The reversal of 198009 is 900891.

198009 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 176400 + 21609 = 420^2 + 147^2 .

It is not a de Polignac number, because 198009 - 2⁸ = 197753 is a prime.

It is a hoax number, since the sum of its digits (27) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (198109) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 217 + ... + 665.

It is an arithmetic number, because the mean of its divisors is an integer number (18525).

2¹⁹⁸⁰⁰⁹ is an apocalyptic number.

It is an amenable number.

198009 is a deficient number, since it is larger than the sum of its proper divisors (135441).

198009 is a wasteful number, since it uses less digits than its factorization.

198009 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 469 (or 459 counting only the distinct ones).

The product of its (nonzero) digits is 648, while the sum is 27.

The square root of 198009 is about 444.9820221088. The cubic root of 198009 is about 58.2856499217.

The spelling of 198009 in words is "one hundred ninety-eight thousand, nine".