转成字符串行吗?
<script language="JavaScript">
var BigNumber="1.23456789876543212E+27";
var i;
var BB=BigNumber.length ;
var bit1=BigNumber.indexOf( '+' ) ;
var bit;
bit=BigNumber.slice(bit1+1,BigNumber.length+1);
BigNumber=BigNumber.substr(0,BigNumber.indexOf( 'E'));
document.write (BigNumber+'<br>');
for (i=0;i<bit;i++)
{ if (BigNumber.slice(i,i+1)!="")
if (!isNaN(BigNumber.slice(i,i+1)))
if (BigNumber.slice(i,i+1)!=".") document.write (BigNumber.slice(i,i+1));
else ;
else ;
else document.write ('0');