Hexbiunium (Hbu)

Hexbiunium is the systematic name of the theoretical 621e element in the periodic table with a symbol of Hbu and atomic number of 621. Hexbiunium, also known as element 621, has zes­honderd­een­en­twintig protons in its nucleus, and zes­honderd­een­en­twintig electrons in its shells.