How to get decimal form of largest known prime?

Tim Peters tim.peters at
Tue Jun 15 05:36:06 CEST 2004

[David M. Cooke]
> ...
> Interesting, because with gmpy (on a 32-bit AMD64 machine running Linux):
> >>> import gmpy
> >>> x = gmpy.mpz(2)**24036583-1
> is almost instantaneous, whereas the straight Python takes a second.

The version of GMP in use is doubtless the reason.  I suspect the
precompiled GMP that ships with mxNumber is getting long in the tooth.

> But then with gmpy I get
> >>> print x
> Segmentation fault
> so I can't win here :-)

That's OK, you don't lose, either <wink>.  Under mxNumber, I tried
stuffing the big prime into a Rational, then displaying it with the
Rational.format(base) method (which some GMP msgs suggested used a
faster base-conversion algorithm for huge numbers), and used
base=1000.  That segfaulted on Windows.

In return for Python's comparative sloth at times, I think I can count
the number of crashes pinned on its bigint implementation over the
last decade on 0 fingers, and the number of bugs on one hand.  It's
one of purest demonstrations of the love affair between simplicity and
reliability I've seen in industrial life.

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