23491 has 6 divisors (see below), whose sum is σ = 25620. Its totient is φ = 21528.

The previous prime is 23473. The next prime is 23497. The reversal of 23491 is 19432.

It is not a de Polignac number, because 23491 - 2⁵ = 23459 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 13.

It is not an unprimeable number, because it can be changed into a prime (23497) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 100 + ... + 238.

It is an arithmetic number, because the mean of its divisors is an integer number (4270).

2²³⁴⁹¹ is an apocalyptic number.

23491 is a deficient number, since it is larger than the sum of its proper divisors (2129).

23491 is a wasteful number, since it uses less digits than its factorization.

23491 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 165 (or 152 counting only the distinct ones).

The product of its digits is 216, while the sum is 19.

The square root of 23491 is about 153.2677395932. The cubic root of 23491 is about 28.6396145252.

It can be divided in two parts, 234 and 91, that added together give a triangular number (325 = T₂₅).

The spelling of 23491 in words is "twenty-three thousand, four hundred ninety-one".