28681589 has 2 divisors, whose sum is σ = 28681590. Its totient is φ = 28681588.

The previous prime is 28681579. The next prime is 28681607. The reversal of 28681589 is 98518682.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 25502500 + 3179089 = 5050^2 + 1783^2 .

It is a cyclic number.

It is not a de Polignac number, because 28681589 - 2⁸ = 28681333 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28681579) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14340794 + 14340795.

It is an arithmetic number, because the mean of its divisors is an integer number (14340795).

Almost surely, 2^28681589 is an apocalyptic number.

It is an amenable number.

28681589 is a deficient number, since it is larger than the sum of its proper divisors (1).

28681589 is an equidigital number, since it uses as much as digits as its factorization.

28681589 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 276480, while the sum is 47.

The square root of 28681589 is about 5355.5194892746. The cubic root of 28681589 is about 306.1031057849.

The spelling of 28681589 in words is "twenty-eight million, six hundred eighty-one thousand, five hundred eighty-nine".