‘倍数’ (bèishù) is a noun meaning 'multiple' — specifically, a number that can be divided evenly by another number without remainder. It combines 倍 (bèi), meaning 'times' or 'fold', and 数 (shù), meaning 'number'. Together, they denote numbers like 6, 9, or 12 — all multiples of 3 — or abstract relationships such as 'three times larger' in comparative contexts.

This term is frequently used in mathematics, science, finance, and everyday comparisons. For example, saying ‘A的收入是B的两倍’ implies A’s income is a multiple of B’s — and ‘两倍’ itself is the multiple. While 倍 alone often appears in phrases like ‘三倍’ (three times), 倍数 emphasizes the resulting number or set of such numbers (e.g., ‘3的倍数’ = multiples of 3). It’s formal but common in both academic and practical usage.