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225 LearnersLast updated on October 8, 2025

The factorial of a number is typically represented with an exclamation mark (!) after it.
For non-negative integers n, the factorial is defined as: n! = n × (n - 1) × (n - 2) × ... × 3 × 2 × 1
However, factorials are not defined for negative numbers in standard mathematics.
Therefore, the factorial of -1 is undefined.
It is important to note that factorials are only applicable to non-negative integers, where 0! is defined as 1 by convention.


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