I search a prime number of the form $$4891625\cdots $$ emerging by concating the perfect powers $p>1$ upto some specific limit $L$ With $L=529$, we get a number splitting into a $31$ and a $48$ digit-prime, so we have no forced small factors. According to my calculation, such a prime must have more than $19\ 000$ digits.
Does a prime of the desired form exist ?