AI engineering glossary · Probability
What is factorial?
Factorial: The product of all whole numbers from 1 up to n, written n!, with 0! defined as 1. It counts the number of ways to arrange n distinct items and appears in the formulas for permutations, combinations and the Poisson distribution.
Factorial: an example
5! = 5 x 4 x 3 x 2 x 1 = 120.
Related terms
More Probability terms
- Frequentist probability
- Gambler's fallacy
- Geometric distribution
- Importance sampling
- Independence
- Intersection of events
- Inverse transform sampling
- Joint distribution
Where you learn it
Factorial is part of the AI Engineering Program, which teaches it with notes, a hands-on lab and an exam. The first lesson is free.