13805 has 8 divisors (see below), whose sum is σ = 18144. Its totient is φ = 10000.

The previous prime is 13799. The next prime is 13807. The reversal of 13805 is 50831.

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

It is not a de Polignac number, because 13805 - 2⁴ = 13789 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a nialpdrome in base 11.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13807) 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, 71 + ... + 180.

It is an arithmetic number, because the mean of its divisors is an integer number (2268).

2¹³⁸⁰⁵ is an apocalyptic number.

It is an amenable number.

13805 is a deficient number, since it is larger than the sum of its proper divisors (4339).

13805 is a wasteful number, since it uses less digits than its factorization.

13805 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 267.

The product of its (nonzero) digits is 120, while the sum is 17.

The square root of 13805 is about 117.4946807307. The cubic root of 13805 is about 23.9889995884.

It can be divided in two parts, 13 and 805, that added together give a palindrome (818).

The spelling of 13805 in words is "thirteen thousand, eight hundred five".