Plaintext and ciphertext block sizes How can you determine the largest plaintext block size and smallest ciphertext size if you used RSA with $n=59768553302699443$ using an alphabet with $27$ characters?
With an alphabet of 27 characters, the maximum number of characters that can fit into one plaintext block is equal to the largest integer less than or equal to $\text{log}(n) / \text{log}(27)$:

$$\bigg\lfloor\frac{\text{log}(59768553302699443)}{\text{log(27)}}\bigg\rfloor = 11$$

On the other hand, assuming the ciphertext is represented as a string of characters in the same alphabet, the minimum ciphertext length will be 12. This is because it will have to accommodate a maximum value of $n$, which is greater than $27^{11}$.