Square either of these 100-digit numbers and the result will terminate with the original number:

395300731910816980293850989006216650958086381100055742342323089610900
4106619977392256259918212890625

604699268089183019706149010993783349041913618899944257657676910389099
5893380022607743740081787109376

Truncate either one from the left, by any number of digits, and it will retain this property.