199881 has 16 divisors (see below), whose sum is σ = 323520. Its totient is φ = 120960.

The previous prime is 199877. The next prime is 199889. The reversal of 199881 is 188991.

It is not a de Polignac number, because 199881 - 2² = 199877 is a prime.

It is a super-2 number, since 2×199881² = 79904828322, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (199889) 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, 40 + ... + 633.

It is an arithmetic number, because the mean of its divisors is an integer number (20220).

2¹⁹⁹⁸⁸¹ is an apocalyptic number.

199881 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

199881 is a deficient number, since it is larger than the sum of its proper divisors (123639).

199881 is a wasteful number, since it uses less digits than its factorization.

199881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 693 (or 687 counting only the distinct ones).

The product of its digits is 5184, while the sum is 36.

The square root of 199881 is about 447.0805296588. The cubic root of 199881 is about 58.4687538594.

The spelling of 199881 in words is "one hundred ninety-nine thousand, eight hundred eighty-one".