Several parts combine into one character.

Compound character: 一 (one) layered on 人 (person). The encoded image: "many people, multiplied" — originally meant "a great mass of people / a thousand people in army formation", later fixed to the precise number 1,000. Identical across 繁體 / 新字体 / 简体. Like 百 (100), 千 retains a "vast quantity" sense in some compounds.

Mandarin: qiān, level 1st tone. 千 (qiān, thousand), 一千 (yīqiān, one thousand), 千万 (qiānwàn, "thousand-myriads" = ten million; also adverbial "by all means / definitely not" depending on context), 千克 (qiānkè, kilogram — "thousand grams"), 千米 (qiānmǐ, kilometer — "thousand meters"), 成千上万 (chéngqiān shàngwàn, "in their thousands and tens of thousands" — countless). Metric units in modern Mandarin uniformly use 千 as the SI thousand-prefix.

Japanese: on-reading セン (sen) — 千 (sen, 1000), 千円 (sen-en, 1000 yen — the most common Japanese banknote denomination, with Noguchi Hideyo on the front), 千年 (sennen, 1000 years / millennium), 数千 (sūsen, several thousand). Kun-reading ち (chi) appears in poetic compounds — 千鳥 (chidori, plover bird — "thousand-bird", a common motif in Japanese pottery and design), 千歳 (chitose, "thousand years" — common name and the name of the 千歳飴 chitose-ame candy given to children at 七五三 Shichi-Go-San coming-of-age festivals), 千葉 (Chiba, prefecture name — "thousand leaves"). The poetic ち reading carries elegant longevity-wishes.

Financial form: 仟 prevents alteration on contracts.

Memory aid: 一 stroke + 人 = a thousand multiplied from one person.