198181 has 4 divisors (see below), whose sum is σ = 201600. Its totient is φ = 194764.

The previous prime is 198179. The next prime is 198193. The reversal of 198181 is 181891.

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 198181 - 2¹ = 198179 is a prime.

It is a super-2 number, since 2×198181² = 78551417522, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (198281) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1621 + ... + 1738.

It is an arithmetic number, because the mean of its divisors is an integer number (50400).

2¹⁹⁸¹⁸¹ is an apocalyptic number.

It is an amenable number.

198181 is a deficient number, since it is larger than the sum of its proper divisors (3419).

198181 is an equidigital number, since it uses as much as digits as its factorization.

198181 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3418.

The product of its digits is 576, while the sum is 28.

The square root of 198181 is about 445.1752463918. The cubic root of 198181 is about 58.3025215965.

Subtracting from 198181 its reverse (181891), we obtain a triangular number (16290 = T₁₈₀).

It can be divided in two parts, 1981 and 81, that multiplied together give a triangular number (160461 = T₅₆₆).

The spelling of 198181 in words is "one hundred ninety-eight thousand, one hundred eighty-one".