diff --git a/lib/integer_palindrome_check.rb b/lib/integer_palindrome_check.rb
index dd4deea..21f7235 100644
--- a/lib/integer_palindrome_check.rb
+++ b/lib/integer_palindrome_check.rb
@@ -1,4 +1,20 @@
 # Returns true if the input positive integer number forms a palindrome. Returns false otherwise.
 def is_palindrome(number)
-  raise NotImplementedError
+  return false if number.nil?
+
+  original = number
+  reverse = 0
+
+  while number > 0
+    last_digit = number % 10
+    reverse = reverse * 10 + last_digit
+    number = number / 10
+  end
+
+  return original == reverse
 end
+
+# Time complexity: linear
+#  Given a number of n digits, the method has a time complexity of O(n). The number of digits is directly proportionate to the the number of times the loop executes.
+# Space complexity: constant
+#  No matter the value of n, the method will require the same amount of memory.