Arrange the 9 numbers from 1 to 9 in a row so that the second number can evenly divide the first number, the third number can evenly divide the sum of the first two numbers, and the fourth number can evenly divide the sum of the first three numbers... The ninth number is divisible by the sum of the first 8 numbers. If the first number is 6, the fourth number is 2, and the fifth number is 1, what is the last number?
将1至9这9个数排成一行，使得第二个数能整除第一个数，第三个数能整除前两个数的和，第四个数能整除前3个数的和…第九个数能整除前8个数的和．如果第一个数是6，第四个数是2，第五个数是1，请问排在最后的数是几？
<result>5</result>