Largest prime factor

3.py

@@ -0,0 +1,16 @@
+def prime_factors(n):
+    """Returns all the prime factors of a positive integer"""
+    factors = []
+    d = 2
+    while n > 1:
+        while n % d == 0:
+            factors.append(d)
+            n /= d
+        d = d + 1
+
+    return factors
+
+
+pfs = prime_factors(600851475143)
+largest_prime_factor = max(pfs)
+print largest_prime_factor