199681611 has 4 divisors (see below), whose sum is σ = 266242152. Its totient is φ = 133121072.

The previous prime is 199681589. The next prime is 199681619. The reversal of 199681611 is 116186991.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 116186991 = 3 ⋅38728997.

It is a cyclic number.

It is not a de Polignac number, because 199681611 - 2¹⁴ = 199665227 is a prime.

It is not an unprimeable number, because it can be changed into a prime (199681619) 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, 33280266 + ... + 33280271.

It is an arithmetic number, because the mean of its divisors is an integer number (66560538).

Almost surely, 2^199681611 is an apocalyptic number.

199681611 is a deficient number, since it is larger than the sum of its proper divisors (66560541).

199681611 is an equidigital number, since it uses as much as digits as its factorization.

199681611 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 66560540.

The product of its digits is 23328, while the sum is 42.

The square root of 199681611 is about 14130.8743890815. The cubic root of 199681611 is about 584.4930577954.

The spelling of 199681611 in words is "one hundred ninety-nine million, six hundred eighty-one thousand, six hundred eleven".