12805 has 8 divisors (see below), whose sum is σ = 16632. Its totient is φ = 9408.

The previous prime is 12799. The next prime is 12809. The reversal of 12805 is 50821.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 2401 + 10404 = 49^2 + 102^2 .

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-12805 is a prime.

It is a Duffinian number.

12805 is an undulating number in base 14.

It is a nialpdrome in base 7.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12809) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 34 + ... + 163.

It is an arithmetic number, because the mean of its divisors is an integer number (2079).

2¹²⁸⁰⁵ is an apocalyptic number.

It is an amenable number.

12805 is a deficient number, since it is larger than the sum of its proper divisors (3827).

12805 is a wasteful number, since it uses less digits than its factorization.

12805 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 215.

The product of its (nonzero) digits is 80, while the sum is 16.

The square root of 12805 is about 113.1591799193. The cubic root of 12805 is about 23.3951873610.

Adding to 12805 its sum of digits (16), we get a palindrome (12821).

It can be divided in two parts, 1280 and 5, that multiplied together give a square (6400 = 80²).

The spelling of 12805 in words is "twelve thousand, eight hundred five".