The word quadrillionths is playable in Words With Friends™, no blanks required. Because it is longer than 7 letters, you would have to play off an existing word or do it in several moves.
Words With Friends™ Letter Score: 30
Highest Scoring Words With Friends™ Plays In The Letters
Seven Letter Word Alert: (73 words)
adhorns, alditol, aliquot, anthill, arillus, astound, astroid, auditor, authors, daltons, diarist, dilator, dishorn, distill, diurnal, dollars, doltish, donairs, dualist, durians, hadrons, hairdos, handout, harlots, idolist, inroads, install, instill, insular, inuloid, lauroid, liaison, liquids, liquors, lithoid, loutish, nitrous, nodular, nostril, nourish, ordains, ordinal, outsail, qindars, qintars, quillon, quinoas, quinoid, quinols, rainout, rations, rituals, rotunda, rotunds, shallot, siliqua, sirloin, squalid, squalor, sundial, tailors, tallish, talonid, tarnish, thallus, thralls, thrills, toadish, tundras, unloads, unrolls, urinals, urolith