9991115 has 4 divisors (see below), whose sum is σ = 11989344. Its totient is φ = 7992888.

The previous prime is 9991067. The next prime is 9991123. The reversal of 9991115 is 5111999.

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 9991115 - 2⁸ = 9990859 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 (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 999107 + ... + 999116.

It is an arithmetic number, because the mean of its divisors is an integer number (2997336).

Almost surely, 2^9991115 is an apocalyptic number.

9991115 is a deficient number, since it is larger than the sum of its proper divisors (1998229).

9991115 is a wasteful number, since it uses less digits than its factorization.

9991115 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1998228.

The product of its digits is 3645, while the sum is 35.

The square root of 9991115 is about 3160.8725061286. The cubic root of 9991115 is about 215.3796429222.

The spelling of 9991115 in words is "nine million, nine hundred ninety-one thousand, one hundred fifteen".