@Albuquerque,
Obviously anything (be it a number or a word) exists in a context. The format of the number you provided without context is an interest one, it is in the form of an IP address.
To answer your question, an IP address is finite. There is actually a problem because this form of IP address has a finite number of possibilities, and we now have more devices then numbers. We have solved this problem by inventing IP6 address (which have a great deal more numbers although still finite).
You can ask if you IP address is real... let me say this.
If I have your IP address I know what computer you are connecting from. I know your ISP. I can very likely (after I have skirted a few security problems) get another set of numbers... your longitude and latitude.
And of course, longitude and latitude are actually quite useful, I they represent an actual spot on the planet. If I have these number, I can very likely get a picture of your house in a matter of seconds.
(To answer the rest of your silly questions, the next number is 1.7.4.2 and the previous one is 1.7.4.1).