199687 has 2 divisors, whose sum is σ = 199688. Its totient is φ = 199686.

The previous prime is 199679. The next prime is 199697. The reversal of 199687 is 786991.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 199687 - 2³ = 199679 is a prime.

It is a zygodrome in base 2.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (199637) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99843 + 99844.

It is an arithmetic number, because the mean of its divisors is an integer number (99844).

2¹⁹⁹⁶⁸⁷ is an apocalyptic number.

199687 is a deficient number, since it is larger than the sum of its proper divisors (1).

199687 is an equidigital number, since it uses as much as digits as its factorization.

199687 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 27216, while the sum is 40.

The square root of 199687 is about 446.8635138384. The cubic root of 199687 is about 58.4498315841.

The spelling of 199687 in words is "one hundred ninety-nine thousand, six hundred eighty-seven".