199905999 has 8 divisors (see below), whose sum is σ = 268330800. Its totient is φ = 132375936.

The previous prime is 199905977. The next prime is 199906051. The reversal of 199905999 is 999509991.

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

It is not a de Polignac number, because 199905999 - 2⁸ = 199905743 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (199903999) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 223162 + ... + 224055.

It is an arithmetic number, because the mean of its divisors is an integer number (33541350).

Almost surely, 2^199905999 is an apocalyptic number.

199905999 is a deficient number, since it is larger than the sum of its proper divisors (68424801).

199905999 is a wasteful number, since it uses less digits than its factorization.

199905999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 447369.

The product of its (nonzero) digits is 2657205, while the sum is 60.

The square root of 199905999 is about 14138.8117959042. The cubic root of 199905999 is about 584.7119130877.

The spelling of 199905999 in words is "one hundred ninety-nine million, nine hundred five thousand, nine hundred ninety-nine".