199911685 has 4 divisors (see below), whose sum is σ = 239894028. Its totient is φ = 159929344.

The previous prime is 199911683. The next prime is 199911689. The reversal of 199911685 is 586119991.

199911685 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 131469156 + 68442529 = 11466^2 + 8273^2 .

It is a cyclic number.

It is not a de Polignac number, because 199911685 - 2¹ = 199911683 is a prime.

It is a Smith number, since the sum of its digits (49) 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 (199911683) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 19991164 + ... + 19991173.

It is an arithmetic number, because the mean of its divisors is an integer number (59973507).

Almost surely, 2^199911685 is an apocalyptic number.

It is an amenable number.

199911685 is a deficient number, since it is larger than the sum of its proper divisors (39982343).

199911685 is an equidigital number, since it uses as much as digits as its factorization.

199911685 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39982342.

The product of its digits is 174960, while the sum is 49.

The square root of 199911685 is about 14139.0128721916. The cubic root of 199911685 is about 584.7174567606.

The spelling of 199911685 in words is "one hundred ninety-nine million, nine hundred eleven thousand, six hundred eighty-five".