9991015 has 8 divisors (see below), whose sum is σ = 12011328. Its totient is φ = 7978080.

The previous prime is 9990997. The next prime is 9991027. The reversal of 9991015 is 5101999.

9991015 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

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

It is not a de Polignac number, because 9991015 - 2⁷ = 9990887 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is a congruent 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 7 ways as a sum of consecutive naturals, for example, 1794 + ... + 4816.

It is an arithmetic number, because the mean of its divisors is an integer number (1501416).

Almost surely, 2^9991015 is an apocalyptic number.

9991015 is a deficient number, since it is larger than the sum of its proper divisors (2020313).

9991015 is a wasteful number, since it uses less digits than its factorization.

9991015 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3689.

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

The square root of 9991015 is about 3160.8566876719. The cubic root of 9991015 is about 215.3789243492.

The spelling of 9991015 in words is "nine million, nine hundred ninety-one thousand, fifteen".