198511 has 4 divisors (see below), whose sum is σ = 199800. Its totient is φ = 197224.

The previous prime is 198503. The next prime is 198529. The reversal of 198511 is 115891.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 198511 - 2³ = 198503 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (198571) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 376 + ... + 733.

It is an arithmetic number, because the mean of its divisors is an integer number (49950).

2¹⁹⁸⁵¹¹ is an apocalyptic number.

198511 is a deficient number, since it is larger than the sum of its proper divisors (1289).

198511 is a wasteful number, since it uses less digits than its factorization.

198511 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1288.

The product of its digits is 360, while the sum is 25.

The square root of 198511 is about 445.5457327817. The cubic root of 198511 is about 58.3348643589.

The spelling of 198511 in words is "one hundred ninety-eight thousand, five hundred eleven".