By using N() function you can enter hidden text in the formula. It is helpful when you want to display any information along with formula in single Cell.
Example : =2018+1056-4*120+N("My Salary + Bonus - 4 weekly loan repayments")
Output := 2594
Note :- Ideally N function is used to convert Non Number value to Number like Dates to Serial Number, True to 1 & anything else to Zero. Hence, the N() function used not be used with text functions otherwise it will result in error.