1 files changed, 47 insertions, 0 deletions
diff --git a/python/helper/numbers.py b/python/helper/numbers.py
new file mode 100644
index 0000000..f99f205
--- /dev/null
+++ b/python/helper/numbers.py
@@ -0,0 +1,47 @@
+from functools import reduce
+from itertools import count
+
+
+def sum_digits(n):
+    return reduce(lambda x, y: x + int(y), str(n), 0)
+
+
+def triangular(n):
+    return n * (n+1) // 2
+
+
+def pentagonal(n):
+    return n * (3*n - 1) // 2
+
+
+def hexagonal(n):
+    return n * (2*n - 1)
+
+
+def is_triangular(n):
+    for i in count(1):
+        t = triangular(i)
+        if t >= n:
+            return t == n
+
+
+# def is_pentagonal(n):
+#     for i in count(1):
+#         p = pentagonal(i)
+#         if p >= n:
+#             return p == n
+
+
+# def is_hexagonal(n):
+#     for i in count(1):
+#         h = hexagonal(i)
+#         if h >= n:
+#             return h == n
+
+
+def proper_divisors(num):
+    divisor = []
+    for i in range(1, num):
+        if num % i == 0:
+            divisor.append(i)
+    return divisor