28493281 has 2 divisors, whose sum is σ = 28493282. Its totient is φ = 28493280.

The previous prime is 28493249. The next prime is 28493299. The reversal of 28493281 is 18239482.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21013056 + 7480225 = 4584^2 + 2735^2 .

It is a cyclic number.

It is not a de Polignac number, because 28493281 - 2⁵ = 28493249 is a prime.

It is a super-2 number, since 2×28493281² = 1623734124289922, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 28493281.

It is not a weakly prime, because it can be changed into another prime (28493981) 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, 14246640 + 14246641.

It is an arithmetic number, because the mean of its divisors is an integer number (14246641).

Almost surely, 2^28493281 is an apocalyptic number.

It is an amenable number.

28493281 is a deficient number, since it is larger than the sum of its proper divisors (1).

28493281 is an equidigital number, since it uses as much as digits as its factorization.

28493281 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 27648, while the sum is 37.

The square root of 28493281 is about 5337.9097969149. The cubic root of 28493281 is about 305.4317311513.

The spelling of 28493281 in words is "twenty-eight million, four hundred ninety-three thousand, two hundred eighty-one".