199999816 has 16 divisors (see below), whose sum is σ = 375994800. Its totient is φ = 99734544.

The previous prime is 199999777. The next prime is 199999819. The reversal of 199999816 is 618999991.

199999816 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not an unprimeable number, because it can be changed into a prime (199999819) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 29950 + ... + 36013.

It is an arithmetic number, because the mean of its divisors is an integer number (23499675).

Almost surely, 2^199999816 is an apocalyptic number.

It is an amenable number.

199999816 is a deficient number, since it is larger than the sum of its proper divisors (175994984).

199999816 is a wasteful number, since it uses less digits than its factorization.

199999816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 66348 (or 66344 counting only the distinct ones).

The product of its digits is 2834352, while the sum is 61.

The square root of 199999816 is about 14142.1291183471. The cubic root of 199999816 is about 584.8033683028.

The spelling of 199999816 in words is "one hundred ninety-nine million, nine hundred ninety-nine thousand, eight hundred sixteen".