William of Auberive
William of Auberive () was a Cistercian monk and numerologist who served as the abbot of from 1165 until 1186. Two of William's treatises—"De sacramentis numerorum a ternario usque ad duodenarium" and "Regule arithmetice"—and three of his letters have been published. He belonged to a group of Cistercians whose work was an expansion on the work of Hugh of Saint-Victor allegorizing numbers in the Bible. His "De sacramentis" on the numbers three (3) through twelve (12) is a direct continuation of the "Analytica numerorum" of Odo of Morimond on the first three natural numbers. It was  itself followed by the work of Geoffrey of Auxerre, beginning with thirteen (13). He was an influence on Theobald of Langres. William probably wrote around 1164, before he became abbot. He knew the "De arithmetica" of Boethius and was especially interested in perfect numbers. He invented some terms of his own. If the aliquot sum of a number was greater than the number, the difference between them he called "fructus" (fruit). If two numbers had identical aliquot sums, the sum was said be the "number of love".