27805 has 8 divisors (see below), whose sum is σ = 34272. Its totient is φ = 21648.

The previous prime is 27803. The next prime is 27809. The reversal of 27805 is 50872.

27805 is nontrivially palindromic in base 9.

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

It is a cyclic number.

It is not a de Polignac number, because 27805 - 2¹ = 27803 is a prime.

It is an Ulam number.

It is a Duffinian number.

27805 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (27803) 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, 294 + ... + 376.

It is an arithmetic number, because the mean of its divisors is an integer number (4284).

2²⁷⁸⁰⁵ is an apocalyptic number.

It is an amenable number.

27805 is a deficient number, since it is larger than the sum of its proper divisors (6467).

27805 is an equidigital number, since it uses as much as digits as its factorization.

27805 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 155.

The product of its (nonzero) digits is 560, while the sum is 22.

The square root of 27805 is about 166.7483133348. The cubic root of 27805 is about 30.2952331960.

The spelling of 27805 in words is "twenty-seven thousand, eight hundred five".