199109 has 2 divisors, whose sum is σ = 199110. Its totient is φ = 199108.

The previous prime is 199103. The next prime is 199151. The reversal of 199109 is 901991.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 178084 + 21025 = 422^2 + 145^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-199109 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (199103) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99554 + 99555.

It is an arithmetic number, because the mean of its divisors is an integer number (99555).

2¹⁹⁹¹⁰⁹ is an apocalyptic number.

It is an amenable number.

199109 is a deficient number, since it is larger than the sum of its proper divisors (1).

199109 is an equidigital number, since it uses as much as digits as its factorization.

199109 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 729, while the sum is 29.

The square root of 199109 is about 446.2163152553. The cubic root of 199109 is about 58.3933821550.

The spelling of 199109 in words is "one hundred ninety-nine thousand, one hundred nine".