The statement of this problem can be found here.

In order to solve this problem the first important thing to notice is how a *repunit* can be represented:

Therefore, we can express if a *repunit* is divisible by *p* like:

So if , then *p* divides .
The problem now is how to calculate the remainder in an efficient way as it is impossible to calculate the remainder to a number of a thousand million digits.
Here we can use Modular exponentiation as what we need to calculate is the remainder of a number than can be expressed as a power with base 10 and exponent 9.

The solution for this code in Python (problem132.py) is really simple (the `CommonFunctions`

file can be found in my wiki):

```
from CommonFunctions import *
from itertools import *
if __name__ == '__main__':
primes = find_primes_less_than(10 ** 6)
base = 10
exp = 10 ** 9
result = sum(islice((p for p in primes if mod_pow(base, exp, 9 * p) == 1), 0, 40))
print("The result is:", result)
```