28507689 has 24 divisors (see below), whose sum is σ = 47511360. Its totient is φ = 16134048.

The previous prime is 28507663. The next prime is 28507697. The reversal of 28507689 is 98670582.

It is not a de Polignac number, because 28507689 - 2⁸ = 28507433 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28507639) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4627 + ... + 8855.

It is an arithmetic number, because the mean of its divisors is an integer number (1979640).

Almost surely, 2^28507689 is an apocalyptic number.

It is an amenable number.

28507689 is a deficient number, since it is larger than the sum of its proper divisors (19003671).

28507689 is a wasteful number, since it uses less digits than its factorization.

28507689 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4349 (or 4346 counting only the distinct ones).

The product of its (nonzero) digits is 241920, while the sum is 45.

The square root of 28507689 is about 5339.2592182811. The cubic root of 28507689 is about 305.4832043254.

The spelling of 28507689 in words is "twenty-eight million, five hundred seven thousand, six hundred eighty-nine".