Python Program to Check Whether a Number is a Perfect Square

Last Updated on 16 March 2025

A perfect square is a number that is the square of an integer. In simple terms, if you can find a whole number that, when multiplied by itself, gives the original number, then it is a perfect square.

Examples of Perfect Squares:

In this tutorial, we will write a Python program to check whether a given number is a perfect square.

Python Program to Check Perfect Square

# Python program to check if a number is a perfect square
import math

# Function to check perfect square
def is_perfect_square(num):
    if num < 0:
        return False  # Negative numbers cannot be perfect squares
    sqrt = math.isqrt(num)  # Get the integer square root
    return sqrt * sqrt == num  # Check if square of sqrt equals num

# Taking user input
number = int(input("Enter a number: "))

# Checking and displaying the result
if is_perfect_square(number):
    print(f"{number} is a perfect square.")
else:
    print(f"{number} is not a perfect square.")

Output

Enter a number: 25
25 is a perfect square.

Using Square Root and Rounding

# Function to check perfect square using square root
def is_perfect_square_alt(num):
    if num < 0:
        return False
    sqrt = num ** 0.5  # Calculate square root
    return sqrt == int(sqrt)  # Check if it's an integer

# Taking user input
number = int(input("Enter a number: "))

# Checking and displaying the result
if is_perfect_square_alt(number):
    print(f"{number} is a perfect square.")
else:
    print(f"{number} is not a perfect square.")

This method uses num ** 0.5 to calculate the square root and checks if it is a whole number.