23391 has 12 divisors (see below), whose sum is σ = 35568. Its totient is φ = 14784.

The previous prime is 23371. The next prime is 23399. The reversal of 23391 is 19332.

23391 = T₆ + T₇ + ... + T₅₁.

It is not a de Polignac number, because 23391 - 2⁶ = 23327 is a prime.

It is a nialpdrome in base 13.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (23399) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 151 + ... + 263.

It is an arithmetic number, because the mean of its divisors is an integer number (2964).

2²³³⁹¹ is an apocalyptic number.

23391 is a deficient number, since it is larger than the sum of its proper divisors (12177).

23391 is a wasteful number, since it uses less digits than its factorization.

23391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 142 (or 139 counting only the distinct ones).

The product of its digits is 162, while the sum is 18.

The square root of 23391 is about 152.9411651584. The cubic root of 23391 is about 28.5989175915.

Adding to 23391 its sum of digits (18), we get a square (23409 = 153²).

It can be divided in two parts, 233 and 91, that added together give a square (324 = 18²).

The spelling of 23391 in words is "twenty-three thousand, three hundred ninety-one".