199309 has 4 divisors (see below), whose sum is σ = 217440. Its totient is φ = 181180.

The previous prime is 199289. The next prime is 199313. The reversal of 199309 is 903991.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 199309 - 2⁷ = 199181 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 12.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (199379) 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, 9049 + ... + 9070.

It is an arithmetic number, because the mean of its divisors is an integer number (54360).

2¹⁹⁹³⁰⁹ is an apocalyptic number.

It is an amenable number.

199309 is a deficient number, since it is larger than the sum of its proper divisors (18131).

199309 is a wasteful number, since it uses less digits than its factorization.

199309 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18130.

The product of its (nonzero) digits is 2187, while the sum is 31.

The square root of 199309 is about 446.4403655585. The cubic root of 199309 is about 58.4129271752.

The spelling of 199309 in words is "one hundred ninety-nine thousand, three hundred nine".