Invertir-numero-con-Divisiones

¿como invertir un numero en c++?
es decir ingreso un numero 1234
y me inprima 4321
#include< iostream.h >

void portada();
void final();

main()
{
int nu;
portada();
cout< < "Numero:";
cin > >nu;
while(nu >10)
{
cout< < (nu%10);
nu=nu/10;
}
cout< < (nu);
final();
system("PAUSE");


}

void portada(){
cout< < ("...............................................................................\a\n");
cout< < ("................******.*****.** **.*****.****.*****.*****..**................\a\n");
cout< < ("................ ** .** **.*** ***.** **.** .** **.**.**.***................\a\n");
cout< < ("................ ** .*****.*******.*****.****.*****.*****..**................\a\n");
cout< < ("................ ** .** **.** * **.** .** .*** ....**..**................\a\n");
cout< < ("................**** .** **.** **.** .****.** **....**.****...............\a\n");
cout< < ("...............................jamper91.hostei.com.............................\a\n");
cout< < ("\n");
};
void final(){
cout< < ("\n-------------------------------------------------------------------------------\a\n");
cout< < ("******************************************************************************\a\n");
cout< < (" Creado por jamper91@hotmail.com\n");
cout< < (" Cucuta Campeon\n");
cout< < ("******************************************************************************\a\n");
cout< < ("-------------------------------------------------------------------------------\a\n");
};