199999915 has 4 divisors (see below), whose sum is σ = 239999904. Its totient is φ = 159999928.

The previous prime is 199999903. The next prime is 199999931. The reversal of 199999915 is 519999991.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 199999915 - 2¹¹ = 199997867 is a prime.

It is a Duffinian number.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 19999987 + ... + 19999996.

It is an arithmetic number, because the mean of its divisors is an integer number (59999976).

Almost surely, 2^199999915 is an apocalyptic number.

199999915 is a deficient number, since it is larger than the sum of its proper divisors (39999989).

199999915 is an equidigital number, since it uses as much as digits as its factorization.

199999915 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39999988.

The product of its digits is 2657205, while the sum is 61.

The square root of 199999915 is about 14142.1326185268. The cubic root of 199999915 is about 584.8034647954.

The spelling of 199999915 in words is "one hundred ninety-nine million, nine hundred ninety-nine thousand, nine hundred fifteen".