The notation "6!" represents the factorial of the number 6. Factorials are a mathematical concept used to calculate the product of all positive integers up to a given number. In this case, 6! means multiplying 6 by every whole number less than it: 6 × 5 × 4 × 3 × 2 × 1. Calculating 6! gives us a total of 720. Factorials are commonly used in various fields, including combinatorics, probability, and statistics, to determine the number of ways to arrange or select items. Understanding factorials is essential for solving problems involving permutations and combinations.