diff --git a/0021.py b/0021.py
new file mode 100644
index 0000000..1c1e86e
--- /dev/null
+++ b/0021.py
@@ -0,0 +1,28 @@
+# amicable pairs
+
+from functools import reduce
+import util
+
+target = 31626
+
+def sum_proper_divisors (nbr):
+    proper_divisors = util.divisors(nbr)[0:-1]
+
+    return reduce(lambda x, y: x + y, proper_divisors)
+
+r = 10000
+
+amicable_numbers = []
+
+for i in range(1, r + 1):
+    s = sum_proper_divisors(i)
+
+    if (s != i and sum_proper_divisors(s) == i):
+        amicable_numbers.append(i)
+
+
+sum_amicables = reduce(lambda x, y: x + y, amicable_numbers)
+
+print(sum_amicables)
+print(sum_amicables == target)
+