This is a harder issue to resolve than it might appear at first glance.
Oganesson element 118, which is the atomic number 118, should contain the highest number of electrons among the atoms which have existed or have been created to date and, having the half-life of just a couple of milliseconds, it lasts long enough to draw local electrons in before it goes through the process of decay. However, Oganesson is produced inside a particle accelerator colliding two nuclei that are lighter It is not known what the conditions are that provide enough electrons for free to fill the Oganesson’s shells prior to it degrades.