198051209 has 4 divisors (see below), whose sum is σ = 198430416. Its totient is φ = 197672004.

The previous prime is 198051199. The next prime is 198051223. The reversal of 198051209 is 902150891.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 198051209 - 2²⁰ = 197002633 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (198051239) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 188819 + ... + 189864.

It is an arithmetic number, because the mean of its divisors is an integer number (49607604).

Almost surely, 2^198051209 is an apocalyptic number.

It is an amenable number.

198051209 is a deficient number, since it is larger than the sum of its proper divisors (379207).

198051209 is an equidigital number, since it uses as much as digits as its factorization.

198051209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 379206.

The product of its (nonzero) digits is 6480, while the sum is 35.

The square root of 198051209 is about 14073.0667944127. The cubic root of 198051209 is about 582.8979115465.

The spelling of 198051209 in words is "one hundred ninety-eight million, fifty-one thousand, two hundred nine".