Etymology Inherited from Middle English sixty, sexty, Old English sixtiġ, from Proto-Germanic *sehs tigiwiz (“sixty”), equivalent to six + -ty. Cognate with Scots sexty, saxty (“sixty”), Saterland Frisian säkstich (“sixty”), West Frisian sechstich (“sixty”), Dutch zestig (“sixty”), German Low German sesstig (“sixty”), German sechzig (“sixty”), Swedish sextio (“sixty”), Norwegian seksti (“sixty”), Icelandic sextíu (“sixty”). Compare also Sanskrit षष्टि (ṣaṣṭi).
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The cardinal number occurring after fifty-nine and before sixty-one, represented in Roman numerals as LX and in Arabic numerals as 60.
[…]the remaining three hundred and sixty words were then vetted with a battery of references. Six potential Mountweazels emerged.2005 August 21, Henry Alford, “Not a Word”, in The New Yorker, →ISSN, archived from the original on 09 Mar 2017:
The first sixty argam form the basis for my own sexagesimal use, in the accounting of my business and in the dimensioning of buildings.2014 November 24, Michael Thomas De Vlieger, “Multiplication Tables of Various Bases”, in The Number Base, archived from the original on 06 Feb 2023, page 43:
Etymology Inherited from Middle English sixty, sexty, Old English sixtiġ, from Proto-Germanic *sehs tigiwiz (“sixty”), equivalent to six + -ty. Cognate with Scots sexty, saxty (“sixty”), Saterland Frisian säkstich (“sixty”), West Frisian sechstich (“sixty”), Dutch zestig (“sixty”), German Low German sesstig (“sixty”), German sechzig (“sixty”), Swedish sextio (“sixty”), Norwegian seksti (“sixty”), Icelandic sextíu (“sixty”). Compare also Sanskrit षष्टि (ṣaṣṭi).
[…] instead of thirties [thirty-second commercials], they buy sixties, which cost twice as much. They spend more on filming it than they need to; they buy a lot of ads that are garbage and don't really say anything, just to fill up the space.2014, Jules Witcover, No Way to Pick a President: