199905 has 8 divisors (see below), whose sum is σ = 319872. Its totient is φ = 106608.

The previous prime is 199889. The next prime is 199909. The reversal of 199905 is 509991.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 199905 - 2⁴ = 199889 is a prime.

It is not an unprimeable number, because it can be changed into a prime (199909) 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, 6649 + ... + 6678.

It is an arithmetic number, because the mean of its divisors is an integer number (39984).

2¹⁹⁹⁹⁰⁵ is an apocalyptic number.

199905 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

199905 is a deficient number, since it is larger than the sum of its proper divisors (119967).

199905 is a wasteful number, since it uses less digits than its factorization.

199905 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13335.

The product of its (nonzero) digits is 3645, while the sum is 33.

The square root of 199905 is about 447.1073696552. The cubic root of 199905 is about 58.4710939083.

The spelling of 199905 in words is "one hundred ninety-nine thousand, nine hundred five".