Nokia never released phones in the 4xxx series (4000, 4100, etc.) because the number 4 is considered unlucky in many East Asian cultures - it sounds similar to the word for 'death' in Chinese, Japanese, Korean, and Vietnamese. While Nokia models like the 3410 and 7650 contained the digit 4 in other positions, the company avoided using 4 as the leading digit until 2019, when they finally released the Nokia 4.2.