Factorial Calculator

1. Enter Value ($n$): Enter a non-negative integer.
2. Click Calculate: Get your factorial value instantly displayed along with scientific notation, total digits, and trailing zeros.

Factorial of any non-negative integer n can be defined as the product of all positive integers that are less than or equal to n. The notation used for factorial is “n!” or n factorial.

n! = n × (n − 1) × (n − 2) × ... × 2 × 1

Special convention: 0! = 1 by mathematical definition.

Example: Calculate 5!.

1. Multiply: 5 × 4 × 3 × 2 × 1 = 120.
2. Result: 120.

Factorials in Combinations and Permutations

Factorials are used to determine the number of ways objects can be arranged:

• There are $52!$ different arrangements of a deck of 52 cards (≈ $8.06 \times 10^{67}$). Each time you shuffle a deck of cards, it is highly unlikely that you have ever produced an identical permutation!