199820209 has 2 divisors, whose sum is σ = 199820210. Its totient is φ = 199820208.

The previous prime is 199820177. The next prime is 199820213. The reversal of 199820209 is 902028991.

199820209 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 158256400 + 41563809 = 12580^2 + 6447^2 .

It is a cyclic number.

It is not a de Polignac number, because 199820209 - 2⁵ = 199820177 is a prime.

It is a super-3 number, since 3×199820209³ (a number of 26 digits) contains 333 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (199820249) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99910104 + 99910105.

It is an arithmetic number, because the mean of its divisors is an integer number (99910105).

Almost surely, 2^199820209 is an apocalyptic number.

It is an amenable number.

199820209 is a deficient number, since it is larger than the sum of its proper divisors (1).

199820209 is an equidigital number, since it uses as much as digits as its factorization.

199820209 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 23328, while the sum is 40.

The square root of 199820209 is about 14135.7776227557. Note that the first 3 decimals coincide. The cubic root of 199820209 is about 584.6282577484.

The spelling of 199820209 in words is "one hundred ninety-nine million, eight hundred twenty thousand, two hundred nine".