199915 has 4 divisors (see below), whose sum is σ = 239904. Its totient is φ = 159928.

The previous prime is 199909. The next prime is 199921. The reversal of 199915 is 519991.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 519991 = 337 ⋅1543.

It is an interprime number because it is at equal distance from previous prime (199909) and next prime (199921).

It is a cyclic number.

It is not a de Polignac number, because 199915 - 2⁹ = 199403 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 19987 + ... + 19996.

It is an arithmetic number, because the mean of its divisors is an integer number (59976).

2¹⁹⁹⁹¹⁵ is an apocalyptic number.

199915 is a deficient number, since it is larger than the sum of its proper divisors (39989).

199915 is an equidigital number, since it uses as much as digits as its factorization.

199915 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39988.

The product of its digits is 3645, while the sum is 34.

The square root of 199915 is about 447.1185525115. The cubic root of 199915 is about 58.4720688734.

The spelling of 199915 in words is "one hundred ninety-nine thousand, nine hundred fifteen".