It does appear "'" & whatever will put the ' in front, unlike you typing it yourself. Who knew.
Anyway, how many digits are these numbers, if you don't mind me asking?
Could be a situation where you need to not format the column as text, but rather change the format from general to number. In general, 123456789012345678 turns into 1.23457E+18. It won't do that formatted as a number. The problem you will run into, however, is that data entered as a number will lose significant digits after the 15th character. so 123456789012345678 turns into 123456789012345000. If you were trying to have 16 character credit card numbers, for example, you've lost that last digit (and you aren't getting it back). To preserve significance on large numeric values, you have to ignore what I said about general and number, and format it as text before entering the large number.
Anyway, once you've formatted the column or cell as text, getting the numeric value back out of it requires you to use =Value(cell ref) in another non-text-formatted cell.