199878 has 16 divisors (see below), whose sum is σ = 456960. Its totient is φ = 57096.

The previous prime is 199877. The next prime is 199889. The reversal of 199878 is 878991.

It is a Harshad number since it is a multiple of its sum of digits (42), and also a Moran number because the ratio is a prime number: 4759 = 199878 / (1 + 9 + 9 + 8 + 7 + 8).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (199873) 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, 2338 + ... + 2421.

It is an arithmetic number, because the mean of its divisors is an integer number (28560).

2¹⁹⁹⁸⁷⁸ is an apocalyptic number.

199878 is an abundant number, since it is smaller than the sum of its proper divisors (257082).

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

199878 is a wasteful number, since it uses less digits than its factorization.

199878 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4771.

The product of its digits is 36288, while the sum is 42.

The square root of 199878 is about 447.0771745460. The cubic root of 199878 is about 58.4684613401.

The spelling of 199878 in words is "one hundred ninety-nine thousand, eight hundred seventy-eight".