199818166 has 4 divisors (see below), whose sum is σ = 299727252. Its totient is φ = 99909082.

The previous prime is 199818163. The next prime is 199818217. The reversal of 199818166 is 661818991.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (199818163) 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 as a sum of consecutive naturals, namely, 49954540 + ... + 49954543.

It is an arithmetic number, because the mean of its divisors is an integer number (74931813).

Almost surely, 2^199818166 is an apocalyptic number.

199818166 is a deficient number, since it is larger than the sum of its proper divisors (99909086).

199818166 is an equidigital number, since it uses as much as digits as its factorization.

199818166 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 99909085.

The product of its digits is 186624, while the sum is 49.

The square root of 199818166 is about 14135.7053591252. The cubic root of 199818166 is about 584.6262652913.

It can be divided in two parts, 1998 and 18166, that added together give a square (20164 = 142²).

The spelling of 199818166 in words is "one hundred ninety-nine million, eight hundred eighteen thousand, one hundred sixty-six".