Is there a way to generate a random UUID, which consists only of numbers?

If you dont want a random number, but an UUID with numbers only use:

String lUUID = String.format("%040d", new BigInteger(UUID.randomUUID().toString().replace("-", ""), 16));

in this case left padded to 40 zeros…

results for:
UUID : b55081fa-9cd1-48c2-95d4-efe2db322a54
in:
UUID : 0241008287272164729465721528295504357972