26661 has 4 divisors (see below), whose sum is σ = 35552. Its totient is φ = 17772.

The previous prime is 26647. The next prime is 26669. The reversal of 26661 is 16662.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 26661 - 2⁶ = 26597 is a prime.

It is a D-number.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 26661.

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, 4441 + ... + 4446.

It is an arithmetic number, because the mean of its divisors is an integer number (8888).

2²⁶⁶⁶¹ is an apocalyptic number.

It is an amenable number.

26661 is a deficient number, since it is larger than the sum of its proper divisors (8891).

26661 is an equidigital number, since it uses as much as digits as its factorization.

26661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8890.

The product of its digits is 432, while the sum is 21.

The square root of 26661 is about 163.2819647114. The cubic root of 26661 is about 29.8739152749.

Subtracting from 26661 its reverse (16662), we obtain a palindrome (9999).

The spelling of 26661 in words is "twenty-six thousand, six hundred sixty-one".