Check if a number is a K-persistent number

Updated

Given two numbers N and K, the task is to check if N is a K-Persistent Number or not. If N is a K-Persistent Number then print “Yes” else print “No”.

A number N is called K-Persistent Number if all of {n, 2n,…, kn} are Pandigital number in base 10.

Examples :

Input : N = 1023456789, K = 2
Output : Yes
Explanation :
1023456789 * 1 = 1023456789 = Pandigital number in base 10
1023456789 * 2 = 2046913578 = Pandigital number in base 10

Input : N = 561, K = 1
Output : No

Approach :

The idea is simple.We iterate through all numbers i from 1 to k and for every integer i in the loop, we check if i*n is a Pandigital number in base 10 or not. If at any i it’s i*n is not Pandigital number in base 10 the return false, otherwise return true at last.

Implementation :

# your code goes here
# python3 program for checking K-Persistent Number
import math 

# Return true if n is pandigital in base 10 else return false.  
def isPandigital(n):  
    
    n = str(n)
    b = 10
  
    hash = [0] * b; 
      
    # Traversing each digit of the number.  
    for i in range(len(n)):  
          
        # If digit is integer  
        if (n[i] >= '0' and n[i] <= '9'):  
            hash[ord(n[i]) - ord('0')] = 1;  
  
        # If digit is alphabet  
        elif (ord(n[i]) - ord('A') <= b - 11):  
            hash[ord(n[i]) - ord('A') + 10] = 1;  
  
    # Checking hash array, if any index is  
    # unmarked.  
    for i in range(b):  
        if (hash[i] == 0):  
            return False  
  
    return True 
    
# Returns true if N is a K-Persistent Number
def isPersistentNumber(N, K):
    for i in range(1, K+1):
        if(isPandigital(i*N)==False):
            return False
    return True
        
    

 
# Driver code
# Given Number N 
N = 1052674893
# Given Number K 
K = 3
# Function Call 
if (isPersistentNumber(N, K)):
    print("Yes")  
else:
    print("No")

Output :

Yes
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Mithlesh Upadhyay Published 14 Nov 2026 · 2 min read

Mithlesh Upadhyay is a Computer Science and AI expert from Madhya Pradesh with strong academic background (BE in CSE and M.Tech in AI) and over six years of experience in technical content development. He has contributed tech articles, led teams, and worked in Full Stack Development and Data Science. He founded the w3colleges.org portal for learning resources.

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