Catching the thief before it's too late

Question

London, 17:15.

Inspector Arbor wasn't quite happy with the current situation. Normally, he would have enjoyed this sunny Saturday outside at the Park but now wasn't the time for that.

Valuable Information about the whereabouts of royal artifacts have been stolen by a mysterious man named "Norman Erdmann". Not much is known about this man other than he hasn't been seen since 1998. Since then he has comitted 58 crimes, well including this one: 59.

Arbor was certain that he had no chance of finding this phantom, no one has ever suceeded in doing so. It was that moment the phone rang.

Following conversation occured.

"Hello? You're speaking with Inspector Arbor".

"Hello, Norman Erdmann here. Have you caught me yet?"

"How did you get my number?"

"Irrelevant. I'm currently stuck for a few minutes so I thought I'll share some clues to the Police. You know, it gets very boring when no one is capeable to catch you."

"I'm listening", said Inspector Arbor while hearing loud engine noises in the phone's background.

"Well, let's see... My favourite numbers are 13 and 36, especially when combined. The clue is the leftover of my previous works, if you understand. Well almost if a fraction of five had not joined the party. But the great thing about 13 is that it's also the second clue."

"I'm not quite sure what you're implying".

"I'm sure you do, Inspector Arbor. Especially if you like math and music."

"Not really, I'm pretty sure you're trying to lead me in the wrong direction!"

"No, no, no Inspector, why would I? If you know what my name and reputation stands for, you'd know that I am leading you in the right direction".

The phone call ended.

Indeed, Inspector Arbor really was an enthusiast in maths and very fond of music. In 10 minutes, Arbor cracked the puzzle and shouted to his secretary: "Quick, connect me to the authorities of ..... and tell them that Norman Erdmann is at ......."

While his orders were executed, Inspector Arbor could only wait and hope of a positive outcome. "Luckily I knew math and could confirm my guess with my knowledge in music", he remarked, while waiting and listening to some classic music.

The authorities of which country did Inspector Arbor contact and what's the location of Norman Erdmann?

Clue 1: If you don't understand, you've to go to the roots of the subject. The answer is primitive, really!

EDIT: Another clue.

Norman Erdmann likes to sign papers with N. E. Also, two of the numbers have a special property to each other. Erdmann learned that fact when he was a "mod" at math.stackexchange

Answer 1

Partial Answer

From the clues:

• Especially if you like math and music
• If you know what my name and reputation stands for, you'd know that I am leading you in the right direction"

I have my doubts on whether the puzzle really require an in-depth knowledge of music as the question itself is not tagged ‘music’. But the name "Norman Erdmann" could relate to Eduard Erdmann, a Baltic German pianist. Hence the above two lines could infer that he is in Germany.

Numbers, 13, 36, 58 (or 59), 1/5

The above numbers could give leads to which postal code in Germany is Norman currently present. From the last clue, it seems like a square root operation is involved and primitive could mean prime. As of now, the idea is to apply some math operations to see which set of numbers yield a valid postal code in Germany.

Hope this helps for others to work on.