diff --git a/Python/12.Highly_Divisible_triangular_number/prajwal-naik.py b/Python/12.Highly_Divisible_triangular_number/prajwal-naik.py
new file mode 100644
index 0000000..8e63d4f
--- /dev/null
+++ b/Python/12.Highly_Divisible_triangular_number/prajwal-naik.py
@@ -0,0 +1,76 @@
+# -*- coding: utf-8 -*-
+"""
+Created on Sat Oct 19 21:15:50 2019
+
+@author: Prajwal
+"""
+#Euler 12
+
+
+def isPrime(n):
+    if(n==1):
+        return 0
+    elif(n<4):
+        return 1
+    elif(n%2==0):
+        return 0
+    elif(n<9):
+        return 1
+    elif(n%3==0):
+        return 0
+    else:
+        r=n**0.5
+        f=5
+        while(f<=r):
+            if((n%f==0) or (n%(f+2)==0)):
+                return 0
+            f+=6
+        return 1
+    
+    
+if __name__=='__main__':
+    n=3
+    Dn=2
+    cnt=0
+    n1=0; Dn1=0; exponent=0;
+    P=200
+    primearray=[]
+    idx=0
+    candidate=1
+    candidate += 1
+    if (isPrime(candidate)):
+        primearray.append(candidate)
+        idx+=1
+    while(idx<P):
+        candidate += 1
+        if (isPrime(candidate)):
+            primearray.append(candidate)
+            idx+=1
+    while(cnt<=500):
+        n+=1
+        n1=n
+        if(n1%2==0):
+            n1/=2
+        Dn1=1
+        for i in range(0, P):
+            if(primearray[i]*primearray[i] > n1):
+                Dn1 *= 2
+                break
+            
+            exponent=1
+            while ( n1% primearray[i] == 0):
+                exponent+=1
+                n1/=primearray[i]
+            if(exponent>1):
+                Dn1*=exponent
+            if(n1==1):
+                break
+        cnt=Dn*Dn1
+        Dn=Dn1
+    print(int((n*(n-1))/2))
+    
+        
+       
+    
+    
+        
diff --git a/README.md b/README.md
index 930ec01..9976a19 100644
--- a/README.md
+++ b/README.md
@@ -40,7 +40,7 @@ Happy Contributing! 😃
 | 09 | [Special Pythagorean triplet](https://projecteuler.net/problem=9)            | :white_check_mark: |                    |                    | :white_check_mark: |                    |                    |                    |    |                    |                     |      |       |
 | 10 | [Summation of primes](https://projecteuler.net/problem=10)                   |                    |                    |                    | :white_check_mark: |                    |                    | :white_check_mark: |    |                    |                     |      |       |
 | 11 | [Largest product in a grid](https://projecteuler.net/problem=11)             |                    |                    |                    | :white_check_mark:                    |                    |                    | :white_check_mark: |    |                    |                     |      |       |
-| 12 | [Highly divisible triangular number](https://projecteuler.net/problem=12)    |                    |                    |                    |                    |                    |                    | :white_check_mark: |    |                    |                     |      |       |
+| 12 | [Highly divisible triangular number](https://projecteuler.net/problem=12)    |                    |                    |                    |  :white_check_mark:                  |                    |                    | :white_check_mark: |    |                    |                     |      |       |
 | 13 | [Large sum](https://projecteuler.net/problem=13)                             | :white_check_mark: |                    |                    | :white_check_mark: |                    |                    |                    |    |                    |                     |      |       |
 | 14 | [Longest Collatz sequence](https://projecteuler.net/problem=14)              |                    |                    |                    |                    |                    |                    |                    |    |                    |                     |      |       |
 | 15 | [Lattice paths](https://projecteuler.net/problem=15)                         |                    |                    |                    |                    |                    |                    |                    |    |                    |                     |      |       |