13765 has 4 divisors (see below), whose sum is σ = 16524. Its totient is φ = 11008.

The previous prime is 13763. The next prime is 13781. The reversal of 13765 is 56731.

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 9409 + 4356 = 97^2 + 66^2 .

It is a cyclic number.

It is not a de Polignac number, because 13765 - 2¹ = 13763 is a prime.

It is a Smith number, since the sum of its digits (22) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13763) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1372 + ... + 1381.

It is an arithmetic number, because the mean of its divisors is an integer number (4131).

2¹³⁷⁶⁵ is an apocalyptic number.

It is an amenable number.

13765 is a deficient number, since it is larger than the sum of its proper divisors (2759).

13765 is an equidigital number, since it uses as much as digits as its factorization.

13765 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2758.

The product of its digits is 630, while the sum is 22.

The square root of 13765 is about 117.3243367763. The cubic root of 13765 is about 23.9658077918.

It can be divided in two parts, 137 and 65, that added together give a palindrome (202).

The spelling of 13765 in words is "thirteen thousand, seven hundred sixty-five".