The number can be in German "die Zahl", "die Nummer" or "die Anzahl". An example for "eine Nummer" is "die Hausnummer" or "die Telefonnummer" of a person. Anzahl: How many guests have come? Answer: "Die Anzahl unserer Gäste (genitive case: of our guests) ist 34." Zahlen: Noch mehr Zahlen, noch mehr Mathematik: ganze Zahlen und Bruchzahlen, positive Zahlen und negative Zahlen, reelle Zahlen und Realzahlen and last not least "die Primzahlen".
Based on what I've figured out so far, I think Zahl doesn't exactly mean "digit"; it means something more like "numeral".
The difference is that a numeral is visible on paper, but a digit is an abstract concept that only exists in the mind (but can be represented using a numeral).
The person speaking the sentence would be talking about some lines or symbols written on paper. The symbols represent numbers, but the person isn't talking about numbers; just the symbols.
So this sentence could mean a really long phone number, or zip code, or PIN, or IP address. It could mean a mathematical equation. Or it might mean a list of numbers.