199861 has 8 divisors (see below), whose sum is σ = 214880. Its totient is φ = 185328.

The previous prime is 199853. The next prime is 199873. The reversal of 199861 is 168991.

199861 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 199861 - 2³ = 199853 is a prime.

It is a Duffinian number.

Its product of digits (3888) is a multiple of the sum of its prime divisors (243).

199861 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (199811) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1195 + ... + 1351.

It is an arithmetic number, because the mean of its divisors is an integer number (26860).

2¹⁹⁹⁸⁶¹ is an apocalyptic number.

It is an amenable number.

199861 is a deficient number, since it is larger than the sum of its proper divisors (15019).

199861 is a wasteful number, since it uses less digits than its factorization.

199861 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 243.

The product of its digits is 3888, while the sum is 34.

The square root of 199861 is about 447.0581617642. The cubic root of 199861 is about 58.4668036756.

The spelling of 199861 in words is "one hundred ninety-nine thousand, eight hundred sixty-one".