번 is a counting unit of time ex) 한번(once, one time) 두번(twice, two times) 저 means "that" 저번 means "that time,the last time" 지난 means "past, last" 저번 is same to 지난번 ex) 저번에 만났을 적에 when I saw him last 저번에 알려 드린 바와 같이 as I let you know last time 저번 is also used as a meaning of 지난 ex) 저번 달 = 지난 달 last month 저번 주 = 지난 주 last week