import re
text = "15159970 (30.12.2015), 15615115 (01.01.1970), 11224455, 55441123 (28.11.2014 12:43:14)"
print( list(filter(None, re.findall(r'\([^()]+\)|(\d+)', text))) )
aW1wb3J0IHJlCgp0ZXh0ID0gIjE1MTU5OTcwICgzMC4xMi4yMDE1KSwgMTU2MTUxMTUgKDAxLjAxLjE5NzApLCAxMTIyNDQ1NSwgNTU0NDExMjMgKDI4LjExLjIwMTQgMTI6NDM6MTQpIgoKcHJpbnQoIGxpc3QoZmlsdGVyKE5vbmUsIHJlLmZpbmRhbGwocidcKFteKCldK1wpfChcZCspJywgdGV4dCkpKSAp