199820 has 24 divisors (see below), whose sum is σ = 428064. Its totient is φ = 78336.

The previous prime is 199819. The next prime is 199831. The reversal of 199820 is 28991.

It is a Smith number, since the sum of its digits (29) coincides with the sum of the digits of its prime factors.

It is an unprimeable number.

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 in 7 ways as a sum of consecutive naturals, for example, 1889 + ... + 1991.

It is an arithmetic number, because the mean of its divisors is an integer number (17836).

2¹⁹⁹⁸²⁰ is an apocalyptic number.

199820 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

199820 is an abundant number, since it is smaller than the sum of its proper divisors (228244).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

199820 is a wasteful number, since it uses less digits than its factorization.

199820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 209 (or 207 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 29.

The square root of 199820 is about 447.0123040812. The cubic root of 199820 is about 58.4628053920.

The spelling of 199820 in words is "one hundred ninety-nine thousand, eight hundred twenty".