The number 2356 in base 10 can be written 2 ×10³ + 3 ×10² + 5 ×10¹ + 6 ×10⁰ = 2000 + 300 + 50 + 6

So the number 234561 in base y can be written 2 ×y⁵ + 3 ×y⁴ + 4×y³ + 5 ×y² + 6 ×y¹ + 1 ×y⁰

How about factorising?