198509871 has 8 divisors (see below), whose sum is σ = 302491264. Its totient is φ = 113434200.

The previous prime is 198509851. The next prime is 198509873. The reversal of 198509871 is 178905891.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 198509871 - 2¹³ = 198501679 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 198509871.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (198509873) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4726405 + ... + 4726446.

It is an arithmetic number, because the mean of its divisors is an integer number (37811408).

Almost surely, 2^198509871 is an apocalyptic number.

198509871 is a deficient number, since it is larger than the sum of its proper divisors (103981393).

198509871 is an equidigital number, since it uses as much as digits as its factorization.

198509871 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9452861.

The product of its (nonzero) digits is 181440, while the sum is 48.

The square root of 198509871 is about 14089.3531079322. The cubic root of 198509871 is about 583.3475376859.

The spelling of 198509871 in words is "one hundred ninety-eight million, five hundred nine thousand, eight hundred seventy-one".