Calculator
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n factorial (n!) multiplies all whole numbers from 1 to n, and counts the ways to arrange n distinct items. It grows extremely fast — 10! is already over three million.
Input is limited to 170 because beyond that the result exceeds the largest number JavaScript can represent and would return infinity. The cap keeps the tab responsive rather than freezing on a runaway number.
That is the promise behind every tool here. Files are read in your browser tab, processed there, and discarded when you close it — never uploaded to our servers.
