How many digits are in the repeating cycle of 17/27?

To find the length of the repeating cycle of a fraction, we need to perform long division until we obtain a repeating pattern.

The division of 17 by 27 is as follows:

```
0.629...
‐‐‐‐‐‐‐‐‐
27 | 17.00
‐ 16
‐‐‐‐‐
10
‐ 9
‐‐‐‐‐
10
‐ 9
‐‐‐‐‐
10
‐ 9
‐‐‐‐‐
1

```

We can see that the pattern repeats every 9 digits: 629629629...

Therefore, the repeating cycle of 17/27 has 9 digits.