23805 has 18 divisors (see below), whose sum is σ = 43134. Its totient is φ = 12144.

The previous prime is 23801. The next prime is 23813. The reversal of 23805 is 50832.

It can be written as a sum of positive squares in only one way, i.e., 19044 + 4761 = 138^2 + 69^2 .

It is not a de Polignac number, because 23805 - 2² = 23801 is a prime.

23805 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (23801) 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 17 ways as a sum of consecutive naturals, for example, 1024 + ... + 1046.

2²³⁸⁰⁵ is an apocalyptic number.

It is an amenable number.

23805 is a deficient number, since it is larger than the sum of its proper divisors (19329).

23805 is a wasteful number, since it uses less digits than its factorization.

23805 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 57 (or 31 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 18.

The square root of 23805 is about 154.2886904475. The cubic root of 23805 is about 28.7666570142.

It can be divided in two parts, 23 and 805, that added together give a palindrome (828).

The spelling of 23805 in words is "twenty-three thousand, eight hundred five".