diff --git a/PerfectNumbers.Core/BigIntegerNumbers.cs b/PerfectNumbers.Core/BigIntegerNumbers.cs
new file mode 100644
index 0000000..984a918
--- /dev/null
+++ b/PerfectNumbers.Core/BigIntegerNumbers.cs
@@ -0,0 +1,15 @@
+using System.Numerics;
+
+namespace PerfectNumbers.Core
+{
+    public static class BigIntegerNumbers
+	{
+		public static readonly BigInteger OneShiftedLeft63 = BigInteger.One << 63;
+		public static readonly BigInteger OneShiftedLeft256MinusOne = (BigInteger.One << 256) - BigInteger.One;
+		public static readonly BigInteger Two = (BigInteger)2;
+		public static readonly BigInteger UlongMaxValue = (BigInteger)ulong.MaxValue; 
+		public static readonly BigInteger UlongMaxValuePlusOne = UlongMaxValue + BigInteger.One;
+		public static readonly BigInteger UInt128MaxValue = (BigInteger)UInt128.MaxValue;
+		public static readonly BigInteger UInt128MaxValuePlusOne = UInt128MaxValue + BigInteger.One;
+	}
+}
\ No newline at end of file
diff --git a/PerfectNumbers.Core/UInt128Numbers.cs b/PerfectNumbers.Core/UInt128Numbers.cs
index f94a331..eae2c50 100644
--- a/PerfectNumbers.Core/UInt128Numbers.cs
+++ b/PerfectNumbers.Core/UInt128Numbers.cs
@@ -7,10 +7,11 @@ namespace PerfectNumbers.Core
         public static readonly UInt128 Two = 2UL;
         public static readonly UInt128 Three = 3UL;
         public static readonly UInt128 Four = 4UL;
-        public static readonly UInt128 SixtyFour = 64UL;
+		public static readonly UInt128 MaxValueMinusOne = UInt128.MaxValue - UInt128.One;
         public static readonly UInt128 OneHundredTwentySeven = 127UL;
         public static readonly UInt128 OneShiftedLeft64 = UInt128.One << 64;
         public static readonly UInt128 OneShiftedLeft64x2 = Two * OneShiftedLeft64;
+        public static readonly UInt128 SixtyFour = 64UL;
 
         public static readonly GpuUInt128 TwoGpu = new(2UL);