Check Strong Number in C, C++, Java & Python – Code with Explanation & Examples in Short and Simple

   

C Program

int fact(int n) {
    int f = 1;
    for (int i = 2; i <= n; i++) f *= i;
    return f;
}

int isStrong(int n) {
    int sum = 0, x = n;
    while (x) {
        sum += fact(x % 10);
        x /= 10;
    }
    return sum == n;
}

C Output

Input:  
145  

Output:  
Yes, Strong Number

C++ Program

int fact(int n) {
    int f = 1;
    for (int i = 2; i <= n; i++) f *= i;
    return f;
}

bool isStrong(int n) {
    int sum = 0, x = n;
    while (x) {
        sum += fact(x % 10);
        x /= 10;
    }
    return sum == n;
}

C++ Output

Input:  
145 

Output:  
true

JAVA Program

int fact(int n) {
    int f = 1;
    for (int i = 2; i <= n; i++) f *= i;
    return f;
}

boolean isStrong(int n) {
    int sum = 0, x = n;
    while (x > 0) {
        sum += fact(x % 10);
        x /= 10;
    }
    return sum == n;
}

JAVA Output

Input:  
145 

Output:  
true

Python Program

def is_strong(n):
    return n == sum(__import__('math').factorial(int(d)) for d in str(n))

Python Output

Input:  
145 

Output:  
True

In-Depth Explanation

Example

Consider number 145.

Divide it into digits: 1, 4, and 5

Now, find the factorial of each digit:

1! = 1

4! = 24

5! = 120

Sum them: 1 + 24 + 120 = 145

Because the sum is the same as the original number, 145 is a Strong Number.

Real-Life Analogy

Suppose there is a unique lock that can be opened only if the "power value" (in this case, factorial) of each digit adds just the right amount to recreate the original code. If every component (digits) plays their role impeccably with their factorial potential, you have a match — a "Strong" identity.

It is similar to a team where every individual does his/her best (factorial contribution), and their combined effort is precisely what the team requires — neither more nor less.

Why It Matters

Strong Numbers are interesting in that they combine digit manipulation with factorial reasoning — two core aspects of programming. It's an excellent exercise in:

Looping

Modular arithmetic

Calculating factorials

Conditional tests

This is also helpful to build logic for digit-level pattern issues in competitive programming and interviews.

What You Learn from This

You gain hands-on experience with:

Dissociating numbers into digits by using modulo and division

Writing or calling a factorial function

Comprehending mathematical number properties

Applying conditions to verify patterns of numbers

It strengthens both mathematical reasoning and loop-based programming, allowing you to tackle analogous problems such as Armstrong numbers, Palindromes, or Krishnamurthy numbers.

Interview Relevance and Actual Projects

This is frequently asked in:

College viva or exams

Logic-building phases of coding interviews

Pattern identification in algorithmic tests

In real application, the same type of problem is useful in:

Validation systems

Mathematical apps or games

Competitive programming sites such as HackerRank or Codeforces

Interviewers use this often to observe how you:

Work with numbers

Optimize redundant calculations

Think computationally in code

SEO-Optimized Explanation

Verification if a number is a Strong Number in C, C++, Java, or Python includes calculating the sum of factorials of its digits and comparing it with the given number. It's a standard start problem which solidifies skills for extracting digits, calculating factorials, looping, and conditional statements. This idea is commonly used in programming interviews and coding contests. With real-world applications in math problems and number theory games, Strong Numbers also assist in creating the basis for more complex algorithmic thinking. Studying this improves your logical reasoning and prepares you for digit analysis and mathematical proof questions in real-world programs.