199000991 has 16 divisors (see below), whose sum is σ = 238245888. Its totient is φ = 162518400.

The previous prime is 199000981. The next prime is 199001009.

It is a happy number.

199000991 is nontrivially palindromic in base 10.

It is a cyclic number.

It is not a de Polignac number, because 199000991 - 2¹⁰ = 198999967 is a prime.

It is a Smith number, since the sum of its digits (38) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (199000931) 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 15 ways as a sum of consecutive naturals, for example, 41351 + ... + 45911.

It is an arithmetic number, because the mean of its divisors is an integer number (14890368).

Almost surely, 2^199000991 is an apocalyptic number.

199000991 is a deficient number, since it is larger than the sum of its proper divisors (39244897).

199000991 is a wasteful number, since it uses less digits than its factorization.

199000991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4862.

The product of its (nonzero) digits is 6561, while the sum is 38.

The square root of 199000991 is about 14106.7711046859. The cubic root of 199000991 is about 583.8282152135.

It can be divided in two parts, 199000 and 991, that added together give a palindrome (199991).

The spelling of 199000991 in words is "one hundred ninety-nine million, nine hundred ninety-one", and thus it is an aban number.