longest running number-one song
... that at 27 weeks, the longest running number-one song on the US Billboard Dance/Electronic Songs chart is "Closer" by The Chainsmokers, featuring Halsey?
... that at 27 weeks, the <b id="mwXg"><a class="mw-redirect" href="./List_of_number-one_Billboard_Dance/Electronic_Songs" id="mwXw" rel="mw:WikiLink" title="List of number-one Billboard Dance/Electronic Songs">longest running number-one song</a></b> on the US <i id="mwYA">Billboard</i> Dance/Electronic Songs chart is "<a href="./Closer_(The_Chainsmokers_song)" id="mwYQ" rel="mw:WikiLink" title="Closer (The Chainsmokers song)">Closer</a>" by <a href="./The_Chainsmokers" id="mwYg" rel="mw:WikiLink" title="The Chainsmokers">The Chainsmokers</a>, featuring <a href="./Halsey_(singer)" id="mwYw" rel="mw:WikiLink" title="Halsey (singer)">Halsey</a>?