Padding with sprintf changing number

[sachin raj aryan]

Hello Monks Not getting why amount is changing after padding with sprintf.Can anyone tell why this kind of output this line print "$amount i m checking amount before padding,\n"; --> output is 488715 this line print "$padamnt i m checking amount after padding,\n"; ---> output is 0000000000488714

sub amnt($amn)
{
my $amount=$_[0];
print "$amount i m checking amount before padding,\n";
my $padamnt = sprintf("%016d",$amount);
print "$padamnt i m checking amount after padding,\n";
 return $padamnt;
}