199939 has 4 divisors (see below), whose sum is σ = 208656. Its totient is φ = 191224.

The previous prime is 199933. The next prime is 199961. The reversal of 199939 is 939991.

199939 = 82² + 83² + ... + 104².

199939 is nontrivially palindromic in base 16.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 939991 = 13 ⋅72307.

It is a cyclic number.

It is not a de Polignac number, because 199939 - 2³ = 199931 is a prime.

It is not an unprimeable number, because it can be changed into a prime (199931) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4324 + ... + 4369.

It is an arithmetic number, because the mean of its divisors is an integer number (52164).

2¹⁹⁹⁹³⁹ is an apocalyptic number.

199939 is a deficient number, since it is larger than the sum of its proper divisors (8717).

199939 is an equidigital number, since it uses as much as digits as its factorization.

199939 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8716.

The product of its digits is 19683, while the sum is 40.

The square root of 199939 is about 447.1453902256. The cubic root of 199939 is about 58.4744086570.

It can be divided in two parts, 19993 and 9, that added together give a palindrome (20002).

The spelling of 199939 in words is "one hundred ninety-nine thousand, nine hundred thirty-nine".