bfac

Return $n! — the factorial of a non-negative integer.

Synopsis

my $x = Math::GMP->new(5);
print $x->bfac;                # 1*2*3*4*5 = 120

The receiver is read as an unsigned long — factorials larger than that range are out of reach of a single call. In practice this is rarely limiting: libgmp struggles with memory long before LONG_MAX enters the picture.