198439018 has 4 divisors (see below), whose sum is σ = 297658530. Its totient is φ = 99219508.

The previous prime is 198439013. The next prime is 198439027. The reversal of 198439018 is 810934891.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 810934891 = 13 ⋅62379607.

It can be written as a sum of positive squares in only one way, i.e., 170380809 + 28058209 = 13053^2 + 5297^2 .

It is not an unprimeable number, because it can be changed into a prime (198439013) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 49609753 + ... + 49609756.

Almost surely, 2^198439018 is an apocalyptic number.

198439018 is a deficient number, since it is larger than the sum of its proper divisors (99219512).

198439018 is an equidigital number, since it uses as much as digits as its factorization.

198439018 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 99219511.

The product of its (nonzero) digits is 62208, while the sum is 43.

The square root of 198439018 is about 14086.8384671650. The cubic root of 198439018 is about 583.2781257866.

The spelling of 198439018 in words is "one hundred ninety-eight million, four hundred thirty-nine thousand, eighteen".