199999909999905 has 16 divisors (see below), whose sum is σ = 320000351999424. Its totient is φ = 106666453333440.

The previous prime is 199999909999889. The next prime is 199999909999909. The reversal of 199999909999905 is 509999909999991.

It is not a de Polignac number, because 199999909999905 - 2⁴ = 199999909999889 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 199999909999794 and 199999909999803.

It is not an unprimeable number, because it can be changed into a prime (199999909999909) 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, 15 + ... + 19999995.

It is an arithmetic number, because the mean of its divisors is an integer number (20000021999964).

Almost surely, 2^{199999909999905} is an apocalyptic number.

199999909999905 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

199999909999905 is a deficient number, since it is larger than the sum of its proper divisors (120000441999519).

199999909999905 is a wasteful number, since it uses less digits than its factorization.

199999909999905 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20666656.

The product of its (nonzero) digits is 156905298045, while the sum is 105.

The spelling of 199999909999905 in words is "one hundred ninety-nine trillion, nine hundred ninety-nine billion, nine hundred nine million, nine hundred ninety-nine thousand, nine hundred five".