28345689 has 6 divisors (see below), whose sum is σ = 40943786. Its totient is φ = 18897120.

The previous prime is 28345679. The next prime is 28345693. The reversal of 28345689 is 98654382.

28345689 is a `hidden beast` number, since 2 + 83 + 4 + 568 + 9 = 666.

It can be written as a sum of positive squares in only one way, i.e., 27910089 + 435600 = 5283^2 + 660^2 .

It is not a de Polignac number, because 28345689 - 2⁵ = 28345657 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28345609) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1574752 + ... + 1574769.

Almost surely, 2^28345689 is an apocalyptic number.

It is an amenable number.

28345689 is a deficient number, since it is larger than the sum of its proper divisors (12598097).

28345689 is a wasteful number, since it uses less digits than its factorization.

28345689 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3149527 (or 3149524 counting only the distinct ones).

The product of its digits is 414720, while the sum is 45.

The square root of 28345689 is about 5324.0669605105. The cubic root of 28345689 is about 304.9034505830.

The spelling of 28345689 in words is "twenty-eight million, three hundred forty-five thousand, six hundred eighty-nine".