What is 13 factorial ?

Steps to calculate factorial of 13

To find 13 factorial, or 13!, simply use the formula that multiplies the number 13 by all positive whole numbers less than it.

Let’s look at how to calculate the Factorial of 13:

13! is exactly :
Factorial of 13 can be calculated as:
13! = 13 x 12 x 11 x 10 x 9 x 8 x 7 x 6 x 5 x 4 x 3 x 2 x 1

Factorials of Numbers similar to 13

What is Factorial?

The term ‘factorial’ represents a mathematical operation where a number is multiplied sequentially by every natural number less than itself down to one. For the number 13, its factorial, written as 13!, is significant because it connects to numerous mathematical concepts integral for solving problems in areas of combinatorics and probability. Understanding the factorial of 13 opens up deeper insights into complex arrangements and calculations within these fields.

Formula to Calculate the Factorial of 13

The basic formula for calculating a factorial is represented as n! = n × (n-1) × … × 1. Applying this to the number 13:

  • 13! = 13 × 12 × 11 × … × 1
  • First, multiply the highest numbers: 13 × 12 = 156
  • Next, multiply by 11: 156 × 11 = 1716
  • Continue this process until you multiply by 1.
  • Eventually, you will reach the value of 13!, which is a large number extending into the billions.

As an example, this large product is crucial for determining the number of ways to arrange 13 distinct objects, and is thus of significant use in various mathematical fields.

What is the Factorial of 13 Used For?

Factorials, such as 13!, play a fundamental role in combinatorics for determining possible permutations of a set. It’s also used in probability theory for calculating the likelihood of certain events. In computer science, algorithms involving factorials are essential in analyzing the complexity of problems. For larger numbers like 13, its factorial has specialized applications such as in cryptography and in creating efficient network designs where a precise number of combinations are critical.


  • 1. If you have 13 different books, in how many ways can you arrange them on a shelf?
  • 2. Consider a 13-team sports league. How many different ways are there to rank the teams from first to last place at the end of the season?
  • 3. How many different 13-digit binary numbers can you create?

Solutions to Exercises

  • 1. The number of ways to arrange the books is equal to the factorial of 13, which is 13!.
  • 2. The rankings can also be determined by 13!, as each distinct ranking is a permutation of the teams.
  • 3. There are 2^13 different 13-digit binary numbers, which is different from computing a factorial but an interesting comparison of combinatorial scale.

Frequently Asked Questions

Q: Is the factorial of 13 used in real-world scenarios?

A: Yes, it’s used in various fields such as engineering, computer science, and statistics where combinations and permutations are key.

Q: What number do you get by calculating the factorial of 13?

A: The factorial of 13 is a large number: 6,227,020,800.

Q: Why is the factorial of zero equal to one?

A: According to the convention of an empty product, multiplying no numbers together results in the multiplicative identity, which is 1. This defines 0! as 1.

Other conversions of the number 13