199819 has 2 divisors, whose sum is σ = 199820. Its totient is φ = 199818.

The previous prime is 199813. The next prime is 199831. The reversal of 199819 is 918991.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 199819 - 2³ = 199811 is a prime.

It is a super-2 number, since 2×199819² = 79855265522, which contains 22 as substring.

199819 is a lucky number.

It is a nialpdrome in base 12.

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, 99909 + 99910.

It is an arithmetic number, because the mean of its divisors is an integer number (99910).

2¹⁹⁹⁸¹⁹ is an apocalyptic number.

199819 is a deficient number, since it is larger than the sum of its proper divisors (1).

199819 is an equidigital number, since it uses as much as digits as its factorization.

199819 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5832, while the sum is 37.

The square root of 199819 is about 447.0111855424. The cubic root of 199819 is about 58.4627078660.

The spelling of 199819 in words is "one hundred ninety-nine thousand, eight hundred nineteen".