198138009 has 16 divisors (see below), whose sum is σ = 285005952. Its totient is φ = 121974528.

The previous prime is 198138001. The next prime is 198138047. The reversal of 198138009 is 900831891.

It is a happy number.

It is not a de Polignac number, because 198138009 - 2³ = 198138001 is a prime.

It is a super-3 number, since 3×198138009³ (a number of 26 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is not an unprimeable number, because it can be changed into a prime (198138001) 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, 33949 + ... + 39354.

It is an arithmetic number, because the mean of its divisors is an integer number (17812872).

Almost surely, 2^198138009 is an apocalyptic number.

It is an amenable number.

198138009 is a deficient number, since it is larger than the sum of its proper divisors (86867943).

198138009 is a wasteful number, since it uses less digits than its factorization.

198138009 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 73376.

The product of its (nonzero) digits is 15552, while the sum is 39.

The square root of 198138009 is about 14076.1503615158. The cubic root of 198138009 is about 582.9830547598.

The spelling of 198138009 in words is "one hundred ninety-eight million, one hundred thirty-eight thousand, nine".