diff --git a/PerfectNumbers.Core/PerfectNumberConstants.cs b/PerfectNumbers.Core/PerfectNumberConstants.cs
index b8b6a40..99f2806 100644
--- a/PerfectNumbers.Core/PerfectNumberConstants.cs
+++ b/PerfectNumbers.Core/PerfectNumberConstants.cs
@@ -3,9 +3,6 @@ namespace PerfectNumbers.Core;
 public static class PerfectNumberConstants
 {
 	public const ulong BiggestKnownEvenPerfectP = 136279841UL;
-	public static readonly uint PrimesLimit = 1_000_000; //(ulong)Array.MaxLength;// 1_000_000;
-
-	// Maximum K for residue-based Mersenne test (q = 2*p*k + 1 up to this k)
-	public static readonly UInt128 ResidueMaxK = 5_000_000UL;
+	public static readonly uint PrimesLimit = 500_000_000; //(ulong)Array.MaxLength;// 1_000_000;
     public const int MaxQForDivisorCycles = 4_000_000;
 }
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