# Check if a number is divisible by 31 or not

Given a number **N**, the task is to check whether the number is divisible by 31 or not. **Examples:**

Input:N = 1922Output:YesExplanation:

31 * 62 = 1922Input:N = 2722400Output:No

**Approach:** The divisibility test of 31 is:

- Extract the last digit.
- Subtract
**3 * last digit**from the remaining number obtained after removing the last digit. - Repeat the above steps until a two-digit number, or zero, is obtained.
- If the two-digit number is divisible by 31, or it is 0, then the original number is also divisible by 31.

**For example:**

If N = 49507Step 1:N = 49507 Last digit = 7 Remaining number = 4950 Subtracting 3 times last digit Resultant number = 4950 - 3*7 = 4929Step 2:N = 4929 Last digit = 9 Remaining number = 492 Subtracting 3 times last digit Resultant number = 492 - 3*9 = 465Step 3:N = 465 Last digit = 5 Remaining number = 46 Subtracting 3 times last digit Resultant number = 46 - 3*5 = 31Step 4:N = 31 Since N is a two-digit number, and 31 is divisible by 31Therefore N = 49507 is also divisible by 31

Below is the implementation of the above approach:

## C++

`// C++ program to check whether a number` `// is divisible by 31 or not` `#include<bits/stdc++.h>` `#include<stdlib.h>` `using` `namespace` `std;` `// Function to check if the number is divisible by 31 or not` `bool` `isDivisible(` `int` `n)` `{` ` ` `int` `d;` ` ` ` ` `// While there are at least two digits` ` ` `while` `(n / 100)` ` ` `{` ` ` `// Extracting the last` ` ` `d = n % 10;` ` ` `// Truncating the number` ` ` `n /= 10;` ` ` `// Subtracting three times the last` ` ` `// digit to the remaining number` ` ` `n = ` `abs` `(n-(d * 3));` ` ` `}` ` ` ` ` `// Finally return if the two-digit` ` ` `// number is divisible by 31 or not` ` ` `return` `(n % 31 == 0) ;` `}` `// Driver Code` `int` `main()` `{` ` ` `int` `N = 1922;` ` ` `if` `(isDivisible(N))` ` ` `cout<<` `"Yes"` `<<endl ;` ` ` `else` ` ` `cout<<` `"No"` `<<endl ;` ` ` ` ` `return` `0; ` `}` `// This code is contributed by ANKITKUMAR34` |

## Java

`// Java program to check whether a number` `// is divisible by 31 or not` `import` `java.util.*;` `class` `GFG{` ` ` `// Function to check if the number is divisible by 31 or not` `static` `boolean` `isDivisible(` `int` `n)` `{` ` ` `int` `d;` ` ` ` ` `// While there are at least two digits` ` ` `while` `((n / ` `100` `) > ` `0` `)` ` ` `{` ` ` ` ` `// Extracting the last` ` ` `d = n % ` `10` `;` ` ` ` ` `// Truncating the number` ` ` `n /= ` `10` `;` ` ` ` ` `// Subtracting three times the last` ` ` `// digit to the remaining number` ` ` `n = Math.abs(n - (d * ` `3` `));` ` ` `}` ` ` ` ` `// Finally return if the two-digit` ` ` `// number is divisible by 31 or not` ` ` `return` `(n % ` `31` `== ` `0` `) ;` `}` ` ` `// Driver Code` `public` `static` `void` `main(String[] args)` `{` ` ` `int` `N = ` `1922` `;` ` ` ` ` `if` `(isDivisible(N))` ` ` `System.out.print(` `"Yes"` `);` ` ` `else` ` ` `System.out.print(` `"No"` `);` `} ` `}` `// This code is contributed by PrinciRaj1992` |

## Python 3

`# Python program to check whether a number` `# is divisible by 31 or not` `# Function to check if the number is` `# divisible by 31 or not` `def` `isDivisible(n) :` ` ` `# While there are at least two digits` ` ` `while` `n ` `/` `/` `100` `:` ` ` `# Extracting the last` ` ` `d ` `=` `n ` `%` `10` ` ` `# Truncating the number` ` ` `n ` `/` `/` `=` `10` ` ` `# Subtracting three times the last` ` ` `# digit to the remaining number` ` ` `n ` `=` `abs` `(n` `-` `(d ` `*` `3` `))` ` ` `# Finally return if the two-digit` ` ` `# number is divisible by 31 or not` ` ` `return` `(n ` `%` `31` `=` `=` `0` `)` `# Driver Code` `if` `__name__ ` `=` `=` `"__main__"` `:` ` ` `n ` `=` `1922` ` ` `if` `(isDivisible(n)) :` ` ` `print` `(` `"Yes"` `)` ` ` `else` `:` ` ` `print` `(` `"No"` `)` |

## C#

`// C# program to check whether a number` `// is divisible by 31 or not` `using` `System;` `class` `GFG{` ` ` `// Function to check if the number is divisible by 31 or not` `static` `bool` `isDivisible(` `int` `n)` `{` ` ` `int` `d;` ` ` ` ` `// While there are at least two digits` ` ` `while` `((n / 100) > 0)` ` ` `{` ` ` ` ` `// Extracting the last` ` ` `d = n % 10;` ` ` ` ` `// Truncating the number` ` ` `n /= 10;` ` ` ` ` `// Subtracting three times the last` ` ` `// digit to the remaining number` ` ` `n = Math.Abs(n - (d * 3));` ` ` `}` ` ` ` ` `// Finally return if the two-digit` ` ` `// number is divisible by 31 or not` ` ` `return` `(n % 31 == 0) ;` `}` ` ` `// Driver Code` `public` `static` `void` `Main(String[] args)` `{` ` ` `int` `N = 1922;` ` ` ` ` `if` `(isDivisible(N))` ` ` `Console.Write(` `"Yes"` `);` ` ` `else` ` ` `Console.Write(` `"No"` `);` `} ` `}` `// This code is contributed by Rajput-Ji` |

## Javascript

`<script>` `// Javascript program to check whether a number` `// is divisible by 31 or not` ` ` `// Function to check if the number is divisible by 31 or not` `function` `isDivisible(n)` `{` ` ` `let d;` ` ` ` ` `// While there are at least two digits` ` ` `while` `(Math.floor(n / 100) > 0)` ` ` `{` ` ` ` ` `// Extracting the last` ` ` `d = n % 10;` ` ` ` ` `// Truncating the number` ` ` `n = Math.floor(n / 10);` ` ` ` ` `// Subtracting three times the last` ` ` `// digit to the remaining number` ` ` `n = Math.abs(n - (d * 3));` ` ` `}` ` ` ` ` `// Finally return if the two-digit` ` ` `// number is divisible by 31 or not` ` ` `return` `(n % 31 == 0) ;` `}` `// Driver Code` ` ` ` ` `let N = 1922;` ` ` ` ` `if` `(isDivisible(N) != 0)` ` ` `document.write(` `"Yes"` `) ;` ` ` `else` ` ` `document.write(` `"No"` `);` `// This code is contributed by sanjoy_62.` `</script>` |

**Output:**

Yes

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