quadrillion
numeral//kwɑˈdɹɪl.i.ən//biljard, kvadriljon
(US, modern British and Australian, short scale) A thousand trillion (logic: 1,000 × 1,0004): 1 followed by fifteen zeros, 1015.
(dated, UK, Australia, long scale) A million trillion (logic: 1,000,0004): 1 followed by twenty-four zeros, 1024.