edd_get_download()
This function can be used to retrieve the post object for a download by either ID or slug.
Example:
$download = edd_get_download(34); // retrieve the download post data for ID 34
$download = edd_get_download('my-awesome-download'); // retrieve the download post data for slug "my-awesome-download"
// you can now do things like this:
$title = $download->post_title;