9991005 has 8 divisors (see below), whose sum is σ = 15985632. Its totient is φ = 5328528.

The previous prime is 9990997. The next prime is 9991027. The reversal of 9991005 is 5001999.

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

It is not a de Polignac number, because 9991005 - 2³ = 9990997 is a prime.

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, 333019 + ... + 333048.

It is an arithmetic number, because the mean of its divisors is an integer number (1998204).

Almost surely, 2^9991005 is an apocalyptic number.

It is an amenable number.

9991005 is a deficient number, since it is larger than the sum of its proper divisors (5994627).

9991005 is a wasteful number, since it uses less digits than its factorization.

9991005 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 666075.

The product of its (nonzero) digits is 3645, while the sum is 33.

The square root of 9991005 is about 3160.8551058218. The cubic root of 9991005 is about 215.3788524917.

The spelling of 9991005 in words is "nine million, nine hundred ninety-one thousand, five".