26561 has 2 divisors, whose sum is σ = 26562. Its totient is φ = 26560.

The previous prime is 26557. The next prime is 26573. The reversal of 26561 is 16562.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 25600 + 961 = 160^2 + 31^2 .

It is a cyclic number.

It is not a de Polignac number, because 26561 - 2² = 26557 is a prime.

It is a Chen prime.

It is a plaindrome in base 12.

It is a nialpdrome in base 14.

It is not a weakly prime, because it can be changed into another prime (26501) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13280 + 13281.

It is an arithmetic number, because the mean of its divisors is an integer number (13281).

2²⁶⁵⁶¹ is an apocalyptic number.

It is an amenable number.

26561 is a deficient number, since it is larger than the sum of its proper divisors (1).

26561 is an equidigital number, since it uses as much as digits as its factorization.

26561 is an evil number, because the sum of its binary digits is even.

The product of its digits is 360, while the sum is 20.

The square root of 26561 is about 162.9754582752. The cubic root of 26561 is about 29.8365181485.

Subtracting from 26561 its reverse (16562), we obtain a palindrome (9999).

The spelling of 26561 in words is "twenty-six thousand, five hundred sixty-one".