199816 has 8 divisors (see below), whose sum is σ = 374670. Its totient is φ = 99904.

The previous prime is 199813. The next prime is 199819. The reversal of 199816 is 618991.

It is an interprime number because it is at equal distance from previous prime (199813) and next prime (199819).

It can be written as a sum of positive squares in only one way, i.e., 198916 + 900 = 446^2 + 30^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is a nialpdrome in base 12.

It is not an unprimeable number, because it can be changed into a prime (199811) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12481 + ... + 12496.

2¹⁹⁹⁸¹⁶ is an apocalyptic number.

It is an amenable number.

199816 is a deficient number, since it is larger than the sum of its proper divisors (174854).

199816 is a wasteful number, since it uses less digits than its factorization.

199816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24983 (or 24979 counting only the distinct ones).

The product of its digits is 3888, while the sum is 34.

The square root of 199816 is about 447.0078299091. The cubic root of 199816 is about 58.4624152862.

The spelling of 199816 in words is "one hundred ninety-nine thousand, eight hundred sixteen".