27865 has 4 divisors (see below), whose sum is σ = 33444. Its totient is φ = 22288.

The previous prime is 27851. The next prime is 27883. The reversal of 27865 is 56872.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 4761 + 23104 = 69^2 + 152^2 .

It is a cyclic number.

It is not a de Polignac number, because 27865 - 2⁷ = 27737 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 8.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2782 + ... + 2791.

It is an arithmetic number, because the mean of its divisors is an integer number (8361).

2²⁷⁸⁶⁵ is an apocalyptic number.

It is an amenable number.

27865 is a deficient number, since it is larger than the sum of its proper divisors (5579).

27865 is an equidigital number, since it uses as much as digits as its factorization.

27865 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5578.

The product of its digits is 3360, while the sum is 28.

The square root of 27865 is about 166.9281282469. The cubic root of 27865 is about 30.3170087529.

It can be divided in two parts, 278 and 65, that added together give a palindrome (343).

The spelling of 27865 in words is "twenty-seven thousand, eight hundred sixty-five".