198818 has 4 divisors (see below), whose sum is σ = 298230. Its totient is φ = 99408.

The previous prime is 198817. The next prime is 198823. The reversal of 198818 is 818891.

198818 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 818891 = 211 ⋅3881.

It can be written as a sum of positive squares in only one way, i.e., 157609 + 41209 = 397^2 + 203^2 .

It is not an unprimeable number, because it can be changed into a prime (198811) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 49703 + ... + 49706.

2¹⁹⁸⁸¹⁸ is an apocalyptic number.

198818 is a deficient number, since it is larger than the sum of its proper divisors (99412).

198818 is an equidigital number, since it uses as much as digits as its factorization.

198818 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 99411.

The product of its digits is 4608, while the sum is 35.

The square root of 198818 is about 445.8901209940. The cubic root of 198818 is about 58.3649207608.

The spelling of 198818 in words is "one hundred ninety-eight thousand, eight hundred eighteen".