198009138 has 16 divisors (see below), whose sum is σ = 396563040. Its totient is φ = 65912256.

The previous prime is 198009083. The next prime is 198009143. The reversal of 198009138 is 831900891.

It is a happy number.

198009138 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 198009096 and 198009105.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 17895 + ... + 26762.

It is an arithmetic number, because the mean of its divisors is an integer number (24785190).

Almost surely, 2^198009138 is an apocalyptic number.

198009138 is an abundant number, since it is smaller than the sum of its proper divisors (198553902).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

198009138 is a wasteful number, since it uses less digits than its factorization.

198009138 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45401.

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

The square root of 198009138 is about 14071.5719804150. The cubic root of 198009138 is about 582.8566346215.

The spelling of 198009138 in words is "one hundred ninety-eight million, nine thousand, one hundred thirty-eight".