diff -r 23cdb1f98069 -r bbd6c6d64b52 src/org/python/core/PyInteger.java
--- a/src/org/python/core/PyInteger.java	Mon Mar 18 21:06:33 2013 -0700
+++ b/src/org/python/core/PyInteger.java	Mon Mar 18 22:59:03 2013 -0700
@@ -38,6 +38,8 @@
     @Deprecated
     public static final BigInteger maxInt = MAX_INT;
 
+    private static final char[] LOOKUP = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f' };
+
     private final int value;
 
     public PyInteger(PyType subType, int v) {
@@ -1090,7 +1092,23 @@
                 format.setGroupingUsed(true);
                 strValue = format.format(value);
             } else if (value instanceof BigInteger) {
-                strValue = ((BigInteger) value).toString(radix);
+                switch (radix) {
+                    /*
+                    case 2:
+                        strValue = toBinString((BigInteger) value);
+                        break;
+                    case 8:
+                        strValue = toOctString((BigInteger) value);
+                        break;
+                    */
+                    case 16:
+                        strValue = toHexString((BigInteger) value);
+                        break;
+                    default:
+                        // TODO: emulate CPython's _PyLong_Format() for efficiency
+                        strValue = ((BigInteger) value).toString(radix);
+                        break;
+                }
             } else {
                 strValue = Integer.toString((Integer) value, radix);
             }
@@ -1123,6 +1141,28 @@
         return spec.pad(strValue, '>', 0);
     }
 
+    static final String toHexString(BigInteger value) {
+        int signum = value.signum();
+
+        // obvious shortcut
+        if (signum == 0)
+            return "0";
+
+        // we want to work in absolute numeric value (negative sign is added afterward)
+        byte[] input = value.abs().toByteArray();
+        char[] output = new char[input.length * 2];
+
+        for (int i = 0; i < input.length; i++) {
+            output[2*i] = LOOKUP[(input[i] >> 4) & 0x0F];
+            output[2*i+1] = LOOKUP[input[i] & 0x0F];
+        }
+
+        // before returning the char array as string, remove leading zeroes, but not the last one
+        String result = new String(output).replaceFirst("^0+(?!$)", "");
+
+        return signum < 0 ? "-" + result : result;
+    }
+
     @Override
     public boolean isIndex() {
         return true;
diff -r 23cdb1f98069 -r bbd6c6d64b52 src/org/python/core/PyLong.java
--- a/src/org/python/core/PyLong.java	Mon Mar 18 21:06:33 2013 -0700
+++ b/src/org/python/core/PyLong.java	Mon Mar 18 22:59:03 2013 -0700
@@ -994,12 +994,19 @@
 
     @ExposedMethod(doc = BuiltinDocs.long___hex___doc)
     final PyString long___hex__() {
-        String s = getValue().toString(16);
-        if (s.startsWith("-")) {
+        /*
+        Issue 2013:
+        getValue() returns a BigInteger object reference, and BigInteger.toString(radix) is known to
+        take computationally expensive time to compute for large numbers.
+         */
+        //String s = getValue().toString(16);
+
+        BigInteger value = getValue();
+        String s = PyInteger.toHexString(value);
+        if (s.startsWith("-"))
             return new PyString("-0x" + s.substring(1, s.length()) + "L");
-        } else {
+        else
             return new PyString("0x" + s + "L");
-        }
     }
 
     @ExposedMethod(doc = BuiltinDocs.long___str___doc)