9591 has 8 divisors (see below), whose sum is σ = 13440. Its totient is φ = 6072.

The previous prime is 9587. The next prime is 9601. The reversal of 9591 is 1959.

It is a happy number.

9591 is a nontrivial binomial coefficient, being equal to C(139, 2).

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

It is not a de Polignac number, because 9591 - 2² = 9587 is a prime.

It is a plaindrome in base 6, base 8, base 13 and base 16.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 9591.

It is not an unprimeable number, because it can be changed into a prime (9511) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1 + ... + 138.

It is an arithmetic number, because the mean of its divisors is an integer number (1680).

2⁹⁵⁹¹ is an apocalyptic number.

9591 is the 138-th triangular number.

9591 is a deficient number, since it is larger than the sum of its proper divisors (3849).

9591 is a wasteful number, since it uses less digits than its factorization.

9591 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 165.

The product of its digits is 405, while the sum is 24.

The square root of 9591 is about 97.9336510092. The cubic root of 9591 is about 21.2465276910.

The spelling of 9591 in words is "nine thousand, five hundred ninety-one".