7. (10 points) In the following arithmetic expression, different Chinese characters represent different digits. If 二零一五 $=2015$, and 数学 is a prime number, then 数学花园 $=$ $\qquad$

保留源文本的换行和格式，直接输出翻译结果。
【Solution】Solution: According to the problem, for the 10 digits from 0 to 9, 2015 uses 4 of them, leaving 3, 4, 6, 7, 8, 9.

The numbers 3 and 9, 4 and 8 are multiples of each other and cannot appear simultaneously in primes, so the product of Garden $\times$ Explore $\times$ Secret is a multiple of 12. It also satisfies the divisibility rule for 3.

The primes are 37, 43, 47, 67, 73, 79, 83, 89, a total of 8 numbers.
When the prime is 37, $2015-37=1978$ is not a multiple of 3.
When the prime is 43, $2015-43=1972$ is not a multiple of 3.
When the prime is 47, $2015-47=1968$ is a multiple of 12. It cannot form a multiplication equation with the remaining numbers 3, 6, 8, 9.

When the prime is 67, $2015-67=1948$ is not a multiple of 3.
When the prime is 73, $2015-73=1942$ is not a multiple of 3.
When the prime is 79, $2015-79=1936$ is not a multiple of 3.
When the prime is 83, $2015-83=1932$ is a multiple of 12. Among the remaining numbers 4, 6, 7, 9, $69 \times 7 \times 4$ $=1902$;

When the prime is 89, $2015-89=1926$ is not a multiple of 12.
$$
2015=83+69 \times 7 \times 4 ;
$$

Therefore, the answer is: 8369