26665 has 4 divisors (see below), whose sum is σ = 32004. Its totient is φ = 21328.

The previous prime is 26647. The next prime is 26669. The reversal of 26665 is 56662.

26665 is nontrivially palindromic in base 4.

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 20736 + 5929 = 144^2 + 77^2 .

It is a cyclic number.

It is not a de Polignac number, because 26665 - 2⁵ = 26633 is a prime.

It is a super-2 number, since 2×26665² = 1422044450, which contains 22 as substring.

It is a Duffinian number.

26665 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (26669) 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, 2662 + ... + 2671.

It is an arithmetic number, because the mean of its divisors is an integer number (8001).

2²⁶⁶⁶⁵ is an apocalyptic number.

It is an amenable number.

26665 is a deficient number, since it is larger than the sum of its proper divisors (5339).

26665 is an equidigital number, since it uses as much as digits as its factorization.

26665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5338.

The product of its digits is 2160, while the sum is 25.

The square root of 26665 is about 163.2942130022. The cubic root of 26665 is about 29.8754092134.

The spelling of 26665 in words is "twenty-six thousand, six hundred sixty-five".