27281 has 2 divisors, whose sum is σ = 27282. Its totient is φ = 27280.

The previous prime is 27277. The next prime is 27283. The reversal of 27281 is 18272.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 25600 + 1681 = 160^2 + 41^2 .

It is a cyclic number.

It is not a de Polignac number, because 27281 - 2² = 27277 is a prime.

It is a super-2 number, since 2×27281² = 1488505922, which contains 22 as substring.

It is a Sophie Germain prime.

Together with 27283, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a nialpdrome in base 8.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 27281.

It is not a weakly prime, because it can be changed into another prime (27283) by changing a digit.

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

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13640 + 13641.

It is an arithmetic number, because the mean of its divisors is an integer number (13641).

2²⁷²⁸¹ is an apocalyptic number.

It is an amenable number.

27281 is a deficient number, since it is larger than the sum of its proper divisors (1).

27281 is an equidigital number, since it uses as much as digits as its factorization.

27281 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 224, while the sum is 20.

The square root of 27281 is about 165.1696097955. The cubic root of 27281 is about 30.1037151001.

Subtracting from 27281 its sum of digits (20), we obtain a triangular number (27261 = T₂₃₃).

Subtracting from 27281 its reverse (18272), we obtain a palindrome (9009).

It can be divided in two parts, 272 and 81, that added together give a palindrome (353).

The spelling of 27281 in words is "twenty-seven thousand, two hundred eighty-one".