Find a number with nine digits d$1,$ d$2,$ d$3,...,$ d$9,$ such that the sub$-$string number d$1,...,$ dn is divisible by n$,1<=$n$<=9.$ That is$,$ the leftmost digit $($d$1)$ is divisible by $1.$ The two leftmost digits $($d$1$ d$2)$ are divisible by $2.$ The three leftmost digits $($d$1$ d$2$ d$3)$ are divisible by $3,$ etc. $($If the above is not clear, assume the number can be displayed as d$1$ d$2$ d$3$ d$4$ d$5$ d$6$ d$7$ d$8$ d$9$ d$10.$ Then d$1$ is divisible by $1,10$d$1+$ d$2$ is divisible by $2,100$d$1+10$d$2+$d$3$ is divisible by $3,$ etc.$)$ What is the number? Note that each of the digits may only be used once.