27785 has 4 divisors (see below), whose sum is σ = 33348. Its totient is φ = 22224.

The previous prime is 27779. The next prime is 27791. The reversal of 27785 is 58772.

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

It is an interprime number because it is at equal distance from previous prime (27779) and next prime (27791).

It can be written as a sum of positive squares in 2 ways, for example, as 19321 + 8464 = 139^2 + 92^2 .

It is a cyclic number.

It is not a de Polignac number, because 27785 - 2⁸ = 27529 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 8 and base 13.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2774 + ... + 2783.

It is an arithmetic number, because the mean of its divisors is an integer number (8337).

2²⁷⁷⁸⁵ is an apocalyptic number.

It is an amenable number.

27785 is a deficient number, since it is larger than the sum of its proper divisors (5563).

27785 is an equidigital number, since it uses as much as digits as its factorization.

27785 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5562.

The product of its digits is 3920, while the sum is 29.

The square root of 27785 is about 166.6883319252. The cubic root of 27785 is about 30.2879677162.

The spelling of 27785 in words is "twenty-seven thousand, seven hundred eighty-five".