9003991 has 4 divisors (see below), whose sum is σ = 9011584. Its totient is φ = 8996400.

The previous prime is 9003977. The next prime is 9003997. The reversal of 9003991 is 1993009.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 1993009 = 1319 ⋅1511.

It is a cyclic number.

It is not a de Polignac number, because 9003991 - 2⁵ = 9003959 is a prime.

It is a Duffinian number.

9003991 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9003997) by changing a digit.

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, 1590 + ... + 4531.

It is an arithmetic number, because the mean of its divisors is an integer number (2252896).

Almost surely, 2^9003991 is an apocalyptic number.

9003991 is a deficient number, since it is larger than the sum of its proper divisors (7593).

9003991 is a wasteful number, since it uses less digits than its factorization.

9003991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7592.

The product of its (nonzero) digits is 2187, while the sum is 31.

The square root of 9003991 is about 3000.6650929419. The cubic root of 9003991 is about 208.0391244820.

The spelling of 9003991 in words is "nine million, three thousand, nine hundred ninety-one".