198218 has 4 divisors (see below), whose sum is σ = 297330. Its totient is φ = 99108.

The previous prime is 198197. The next prime is 198221. The reversal of 198218 is 812891.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 812891 = 257 ⋅3163.

It can be written as a sum of positive squares in only one way, i.e., 146689 + 51529 = 383^2 + 227^2 .

It is an Ulam number.

It is a Curzon number.

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 49553 + ... + 49556.

2¹⁹⁸²¹⁸ is an apocalyptic number.

198218 is a deficient number, since it is larger than the sum of its proper divisors (99112).

198218 is an equidigital number, since it uses as much as digits as its factorization.

198218 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 99111.

The product of its digits is 1152, while the sum is 29.

The square root of 198218 is about 445.2168011205. The cubic root of 198218 is about 58.3061496925.

The spelling of 198218 in words is "one hundred ninety-eight thousand, two hundred eighteen".