199800191 has 2 divisors, whose sum is σ = 199800192. Its totient is φ = 199800190.

The previous prime is 199800187. The next prime is 199800199. The reversal of 199800191 is 191008991.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 199800191 - 2² = 199800187 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (199800199) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99900095 + 99900096.

It is an arithmetic number, because the mean of its divisors is an integer number (99900096).

Almost surely, 2^199800191 is an apocalyptic number.

199800191 is a deficient number, since it is larger than the sum of its proper divisors (1).

199800191 is an equidigital number, since it uses as much as digits as its factorization.

199800191 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5832, while the sum is 38.

The square root of 199800191 is about 14135.0695435148. The cubic root of 199800191 is about 584.6087343990.

It can be divided in two parts, 199800 and 191, that added together give a palindrome (199991).

The spelling of 199800191 in words is "one hundred ninety-nine million, eight hundred thousand, one hundred ninety-one".