On Akkadian šu-ši : A Linguistic Consequence of the Adoption of the Sexagesimal Number System

Abstract The well-known borrowing of the Sumerian sexagesimal number system by Akkadians manifests itself not only within the domain of numerical notation, but also in the forms of the underlying Akkadian number words and their syntactic structure. Here, one linguistic consequence of the adoption of the sexagesimal system is addressed, the long-standing issue of the form and etymology of the Akkadian šu-ši ‘sixty’. The article puts forth the following claims: first, that the original Akkadian word for 60 was not šu-ši but *še/iššā; second, that the original *še/iššā was not suitable to function as a base within the newly adopted sexagesimal system; and, finally, that the new base šu-ši, which supplanted the original Akkadian word for 60, represents a repurposing of the fraction šuššu ‘one-sixth’. The arguments are grounded in historical linguistics and typology, relying on a combination of internal Akkadian, comparative Semitic, and cross-linguistic evidence.