199659 has 4 divisors (see below), whose sum is σ = 266216. Its totient is φ = 133104.

The previous prime is 199657. The next prime is 199669. The reversal of 199659 is 956991.

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

It is not a de Polignac number, because 199659 - 2¹ = 199657 is a prime.

It is a D-number.

It is a Duffinian number.

It is a nialpdrome in base 12.

It is not an unprimeable number, because it can be changed into a prime (199657) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 33274 + ... + 33279.

It is an arithmetic number, because the mean of its divisors is an integer number (66554).

2¹⁹⁹⁶⁵⁹ is an apocalyptic number.

199659 is a deficient number, since it is larger than the sum of its proper divisors (66557).

199659 is an equidigital number, since it uses as much as digits as its factorization.

199659 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 66556.

The product of its digits is 21870, while the sum is 39.

The square root of 199659 is about 446.8321832635. The cubic root of 199659 is about 58.4470995221.

It can be divided in two parts, 199 and 659, that added together give a palindrome (858).

The spelling of 199659 in words is "one hundred ninety-nine thousand, six hundred fifty-nine".