199831 has 2 divisors, whose sum is σ = 199832. Its totient is φ = 199830.

The previous prime is 199819. The next prime is 199853. The reversal of 199831 is 138991.

199831 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 199831 - 2⁵ = 199799 is a prime.

It is a super-2 number, since 2×199831² = 79864857122, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 199793 and 199802.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (199811) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99915 + 99916.

It is an arithmetic number, because the mean of its divisors is an integer number (99916).

2¹⁹⁹⁸³¹ is an apocalyptic number.

199831 is a deficient number, since it is larger than the sum of its proper divisors (1).

199831 is an equidigital number, since it uses as much as digits as its factorization.

199831 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1944, while the sum is 31.

The square root of 199831 is about 447.0246078238. The cubic root of 199831 is about 58.4638781559.

The spelling of 199831 in words is "one hundred ninety-nine thousand, eight hundred thirty-one".