43是质数==>a（1）=0。
3661 = 7 * 523.
360601 = 19 * 18979.
36006001 = 67 * 537403.
3600060001 = 457 * 7877593.
360000600001 = 7 * 51428657143.
36000006000001 = 379 * 94986823219.
3600000060000001 = 7 * 43 * 64609 * 185115589.
360000000600000001 = 19 * 18947368452631579.
36000000006000000001 = 307 * 1249 * 1071121 * 87652267.
360000000060000000001是质数==>a（2）=10。
