Pronic numbers are those numbers who can be written as a product of two consecutive integers.
It means, they are of the form: P = n * (n + 1)
For example, the number 56 can be written as 7 * 8, that is, a product of two consecutive integers.
Hence, the number 56 is a Pronic number.
Pronic numbers are also called oblong numbers, heteromecic numbers, or rectangular numbers.
Some of the Pronic numbers are: 0, 2, 6, 12, 20, 30, 42, 56, 72, 90, 110 …
Below is a program that inputs a number, and checks whether it is a Pronic number or not.
public class PronicNumber
static void checkForPronic(int number)
int squareRoot = (int)Math.sqrt(number);
int product = squareRoot * (squareRoot + 1);
if(product == number)
System.out.println("The number is a Pronic number");
System.out.println("The number is not a Pronic number");
public static void main (String args)
Scanner input = new Scanner(System.in);
System.out.print("Enter a Number: ");
int number = input.nextInt();
The program runs on the following algorithm to check whether a number is Pronic or not.
- Calculate the square root of number and taking floor of the number by typecasting it to
- Find the product of the squareRoot and (squareRoot + 1), and then compare the product with the number.
We used the java.lang.Math function sqrt(), to calculate the square root.
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