28008689 has 2 divisors, whose sum is σ = 28008690. Its totient is φ = 28008688.

The previous prime is 28008683. The next prime is 28008703. The reversal of 28008689 is 98680082.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21160000 + 6848689 = 4600^2 + 2617^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28008689 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (28008683) 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, 14004344 + 14004345.

It is an arithmetic number, because the mean of its divisors is an integer number (14004345).

Almost surely, 2^28008689 is an apocalyptic number.

It is an amenable number.

28008689 is a deficient number, since it is larger than the sum of its proper divisors (1).

28008689 is an equidigital number, since it uses as much as digits as its factorization.

28008689 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 55296, while the sum is 41.

The square root of 28008689 is about 5292.3235917695. The cubic root of 28008689 is about 303.6903045599.

The spelling of 28008689 in words is "twenty-eight million, eight thousand, six hundred eighty-nine".