Assume that the middle two numbers of a 4-digit integer N are "1" and "2", the arrangement order is "12", and N is an integer multiple of 15. What is the largest natural number N that satisfies the condition?
假设已知一个4位整数N的中间两个数字是"1"和"2"，排列顺序是"12"，并且N是15的整倍数．请问满足条件的自然数N最大是多少．
<result>9_120</result>