199999009 has 4 divisors (see below), whose sum is σ = 228570304. Its totient is φ = 171427716.

The previous prime is 199999001. The next prime is 199999043. The reversal of 199999009 is 900999991.

It is a happy number.

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 199999009 - 2³ = 199999001 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (199999001) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 14285637 + ... + 14285650.

It is an arithmetic number, because the mean of its divisors is an integer number (57142576).

Almost surely, 2^199999009 is an apocalyptic number.

It is an amenable number.

199999009 is a deficient number, since it is larger than the sum of its proper divisors (28571295).

199999009 is an equidigital number, since it uses as much as digits as its factorization.

199999009 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28571294.

The product of its (nonzero) digits is 531441, while the sum is 55.

The square root of 199999009 is about 14142.1005865465. The cubic root of 199999009 is about 584.8025817405.

The spelling of 199999009 in words is "one hundred ninety-nine million, nine hundred ninety-nine thousand, nine".