199865 has 8 divisors (see below), whose sum is σ = 243648. Its totient is φ = 157360.

The previous prime is 199853. The next prime is 199873. The reversal of 199865 is 568991.

199865 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is not a de Polignac number, because 199865 - 2¹⁰ = 198841 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 74 + ... + 636.

It is an arithmetic number, because the mean of its divisors is an integer number (30456).

2¹⁹⁹⁸⁶⁵ is an apocalyptic number.

It is an amenable number.

199865 is a deficient number, since it is larger than the sum of its proper divisors (43783).

199865 is an equidigital number, since it uses as much as digits as its factorization.

199865 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 639.

The product of its digits is 19440, while the sum is 38.

The square root of 199865 is about 447.0626354327. The cubic root of 199865 is about 58.4671937228.

It can be divided in two parts, 19986 and 5, that added together give a palindrome (19991).

The spelling of 199865 in words is "one hundred ninety-nine thousand, eight hundred sixty-five".