198161 has 4 divisors (see below), whose sum is σ = 201024. Its totient is φ = 195300.

The previous prime is 198139. The next prime is 198173. The reversal of 198161 is 161891.

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 198161 - 2⁶ = 198097 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 198161.

It is not an unprimeable number, because it can be changed into a prime (198461) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1325 + ... + 1466.

It is an arithmetic number, because the mean of its divisors is an integer number (50256).

2¹⁹⁸¹⁶¹ is an apocalyptic number.

It is an amenable number.

198161 is a deficient number, since it is larger than the sum of its proper divisors (2863).

198161 is an equidigital number, since it uses as much as digits as its factorization.

198161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2862.

The product of its digits is 432, while the sum is 26.

The square root of 198161 is about 445.1527827612. The cubic root of 198161 is about 58.3005602756.

Subtracting from 198161 its sum of digits (26), we obtain a triangular number (198135 = T₆₂₉).

It can be divided in two parts, 198 and 161, that multiplied together give a triangular number (31878 = T₂₅₂).

The spelling of 198161 in words is "one hundred ninety-eight thousand, one hundred sixty-one".