198661818 has 8 divisors (see below), whose sum is σ = 397323648. Its totient is φ = 66220604.

The previous prime is 198661807. The next prime is 198661823. The reversal of 198661818 is 818166891.

It is a sphenic number, since it is the product of 3 distinct primes.

198661818 is an admirable number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16555146 + ... + 16555157.

It is an arithmetic number, because the mean of its divisors is an integer number (49665456).

Almost surely, 2^198661818 is an apocalyptic number.

198661818 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

198661818 is a wasteful number, since it uses less digits than its factorization.

198661818 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33110308.

The product of its digits is 165888, while the sum is 48.

The square root of 198661818 is about 14094.7443396466. The cubic root of 198661818 is about 583.4963385186.

The spelling of 198661818 in words is "one hundred ninety-eight million, six hundred sixty-one thousand, eight hundred eighteen".