助番[sukeban] leader of a female gang
ブロック番号[burokkubangou] block number
暗唱番号[anshoubangou] personal identification number
一貫番号[ikkanbangou] serial number
一番[ichiban] best

一番[hitotsugai] pair
一番鶏[ichibandori] first cockcrowing
一番手[ichibante] first player
一番乗り[ichibannori] leader of a charge
一番線[ichibansen] track no. 1

一週[isshuu] one week
一週間[isshuukan] one week
今週[konshuu] this week
今週中に[konshuujuuni] before the week is out
さ来週[saraishuu] week after next

七週の祭[nanamawarinoiwai] the Feast of Weeks
七週の祭り[nanashuunomatsuri] the Feast of Weeks
週刊[shuukan] published weekly
週刊雑誌[shuukanzasshi] weekly magazine