factorial (length)

My code can pass the check if I wrote as below, but not work if wrote in CODEB as below when length is GE 24, what's the problem inside?

CODEB : diff = (((math.factorial(length))*interval)) /length

\`    FULL CODE:\`
    \`from typing import Iterable\`
    \`import math\`
    \`\`
    \`def reversed_permutation_index(length: int, index: int):\`
    \`    num_list=list(range(length))\`
    \`    result=[]\`
    \`    while (length>0 ):\`
    \`        interval = math.ceil((length*index/math.factorial(length))) -1\`
    \`        diff = (((math.factorial(length-1))*interval))\`
    \`        index -=diff\`
    \`        print (interval, diff)\`
    \`        result.append(num_list[interval])\` 
    \`        num_list.remove(num_list[interval])\` 
    \`        length-=1\`
    \`    return result\`