Interesting detail: Each Safecoin has a unique ID.

There will be no more than 2^32 Safecoins, which is about 4.3 billion. Each of them will have a unique ID, but still they will be divisible.

Safecoin, the currency of the SAFE network, is generated in response to network use. As stored data is retrieved, or as apps are created and used, the network generates safecoins, each with their own unique ID. As these coins are divisible, each new denomination is allocated a new and completely unique ID.

What I don't know is that if I recieve 0.25 Safecoins from someone, and 0.20 from someone else, each with unique ID:s, will the coins be combined into a new one with a new ID, or will they be two separate coins, which I can send forward. It seems to me this must be the case, since otherwise the owners of the coins could not be tracked, which is the basis of the coin:

Unlike bitcoin, the SAFE Network does not use a blockchain to manage ownership of coins. Conversely, the SAFE Network’s Transaction Managers are unchained, meaning that only the past and current coin owner is known. It is helpful to think of safecoin as digital cash in this respect.

Now this is kind of funny. One's balance isn't only the sum of inputs and outputs, like in all other cryptocurrencies, but a collection of arbitrarily sized unique coins. I would pay someone else with a 0.382663 coin and a 0.777722 coin, both with their own identity. Could this result in some special coin being valued more than an other, because some celebrity has owned it?

Quote's from the Safenetwork wiki.