Probably this might help

my $foo = "12314212412124124124.10623";
my $text = int(sprintf("%0.2f", $foo));

print $text,"\n";
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I think since the number is too huge that is why it is not able to round it off. Double Precision works for 15 digits of precision and a range of at least 1e-100 to 1e100. You can read about it here