27765 has 12 divisors (see below), whose sum is σ = 48204. Its totient is φ = 14784.

The previous prime is 27763. The next prime is 27767. The reversal of 27765 is 56772.

It is an interprime number because it is at equal distance from previous prime (27763) and next prime (27767).

It can be written as a sum of positive squares in 2 ways, for example, as 4356 + 23409 = 66^2 + 153^2 .

It is not a de Polignac number, because 27765 - 2¹ = 27763 is a prime.

It is a d-powerful number, because it can be written as 2³ + 7² + 7⁵ + 6⁵ + 5⁵ .

27765 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (27763) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 264 + ... + 353.

It is an arithmetic number, because the mean of its divisors is an integer number (4017).

2²⁷⁷⁶⁵ is an apocalyptic number.

It is an amenable number.

27765 is a deficient number, since it is larger than the sum of its proper divisors (20439).

27765 is a wasteful number, since it uses less digits than its factorization.

27765 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 628 (or 625 counting only the distinct ones).

The product of its digits is 2940, while the sum is 27.

The square root of 27765 is about 166.6283289240. The cubic root of 27765 is about 30.2806987490.

The spelling of 27765 in words is "twenty-seven thousand, seven hundred sixty-five".