Xiaojun's phone number is a seven-digit number, the first three numbers are the same, and the sum is 15. Among the last 4 numbers, the last number is twice the previous number. What is Xiaojun's phone number?
小军家电话号码是一个七位数，前3个数字是一样的，和是15．后4个数中，后一个数字都是前一个数字的2倍．小军家的电话号码是多少．
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