At 1:33 we have: 两个多小时 "more than two hours". When 多 means "more than", I think it usually comes after two characters. So "more than twenty hours" should be: 二十多个小时。 This means that 个 sometimes comes before 多, and sometimes after 多。
2‹ 两个多 ‹3，for example 2.6 两个多小时 = 两个小时多 = 两小时多 20多个小时=from 20 to 30 hours，for example 25 20‹ 20年多 ‹21，over 20 years，for example 20.3 20多年 = 21-29, twenties，for example 27 20多个人 ，21-29，for example 28 20个多人 is wrong，for example 20.5 people is wrong
when the numeral is less than 10, 多 is put behind the measure word (量词: 个, etc.). When the numeral is greater than 10 多 is put before the measure word. You can find this grammar point in the first lessons in the HSK 2 standard course book. Hope this helps.
