28137281 has 2 divisors, whose sum is σ = 28137282. Its totient is φ = 28137280.

The previous prime is 28137259. The next prime is 28137283. The reversal of 28137281 is 18273182.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16679056 + 11458225 = 4084^2 + 3385^2 .

It is a cyclic number.

It is not a de Polignac number, because 28137281 - 2¹⁰ = 28136257 is a prime.

It is a super-2 number, since 2×28137281² = 1583413164145922, which contains 22 as substring.

It is a Sophie Germain prime.

Together with 28137283, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (28137283) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14068640 + 14068641.

It is an arithmetic number, because the mean of its divisors is an integer number (14068641).

Almost surely, 2^28137281 is an apocalyptic number.

It is an amenable number.

28137281 is a deficient number, since it is larger than the sum of its proper divisors (1).

28137281 is an equidigital number, since it uses as much as digits as its factorization.

28137281 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5376, while the sum is 32.

The square root of 28137281 is about 5304.4585963131. The cubic root of 28137281 is about 304.1543573509.

The spelling of 28137281 in words is "twenty-eight million, one hundred thirty-seven thousand, two hundred eighty-one".