According to the stem analysis, we can get: good =2222, so wonderful+math+garden =2222-2007=2 15,

And to minimize this six figures, beauty is the smallest and beauty is also small. Beauty+number+flower =20 or 2 1,

If it is equal to 20, the maximum number of flowers is 17, so beauty =3,

And because wonderful = good =2, contradiction,

So Miao =4, number =8, learning =5, flower =9, garden =6,

So this number is 348596,

Therefore, the six digits represented by the "wonderful mathematical garden" are at least 348596.

So the answer is: 348596.