199857 has 16 divisors (see below), whose sum is σ = 315392. Its totient is φ = 110160.

The previous prime is 199853. The next prime is 199873. The reversal of 199857 is 758991.

It is a happy number.

It is not a de Polignac number, because 199857 - 2² = 199853 is a prime.

It is not an unprimeable number, because it can be changed into a prime (199853) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 498 + ... + 804.

It is an arithmetic number, because the mean of its divisors is an integer number (19712).

2¹⁹⁹⁸⁵⁷ is an apocalyptic number.

It is an amenable number.

199857 is a deficient number, since it is larger than the sum of its proper divisors (115535).

199857 is a wasteful number, since it uses less digits than its factorization.

199857 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 348.

The product of its digits is 22680, while the sum is 39.

The square root of 199857 is about 447.0536880510. The cubic root of 199857 is about 58.4664136232.

The spelling of 199857 in words is "one hundred ninety-nine thousand, eight hundred fifty-seven".