198917818 has 16 divisors (see below), whose sum is σ = 332429184. Its totient is φ = 88492960.

The previous prime is 198917801. The next prime is 198917819. The reversal of 198917818 is 818719891.

It is a super-2 number, since 2×198917818² = 79136596635762248, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (198917819) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 95155 + ... + 97222.

It is an arithmetic number, because the mean of its divisors is an integer number (20776824).

Almost surely, 2^198917818 is an apocalyptic number.

198917818 is a deficient number, since it is larger than the sum of its proper divisors (133511366).

198917818 is a wasteful number, since it uses less digits than its factorization.

198917818 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 192437.

The product of its digits is 290304, while the sum is 52.

The square root of 198917818 is about 14103.8228151094. The cubic root of 198917818 is about 583.7468663542.

The spelling of 198917818 in words is "one hundred ninety-eight million, nine hundred seventeen thousand, eight hundred eighteen".