26681 has 2 divisors, whose sum is σ = 26682. Its totient is φ = 26680.

The previous prime is 26669. The next prime is 26683. The reversal of 26681 is 18662.

26681 = 115² + 116².

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13456 + 13225 = 116^2 + 115^2 .

It is a cyclic number.

It is not a de Polignac number, because 26681 - 2¹⁰ = 25657 is a prime.

It is a super-2 number, since 2×26681² = 1423751522, which contains 22 as substring.

Together with 26683, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (26683) by changing a digit.

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

It is a good prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13340 + 13341.

It is an arithmetic number, because the mean of its divisors is an integer number (13341).

2²⁶⁶⁸¹ is an apocalyptic number.

26681 is the 116-th centered square number.

It is an amenable number.

26681 is a deficient number, since it is larger than the sum of its proper divisors (1).

26681 is an equidigital number, since it uses as much as digits as its factorization.

26681 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 576, while the sum is 23.

The square root of 26681 is about 163.3431969811. The cubic root of 26681 is about 29.8813834740.

It can be divided in two parts, 26 and 681, that added together give a palindrome (707).

The spelling of 26681 in words is "twenty-six thousand, six hundred eighty-one".