Find the next number in the series: $144,169,196,225,?$

Let's analyze the given series:
* $144=12^2$
* $169=13^2$
* $196=14^2$
* $225=15^2$

The series consists of squares of consecutive natural numbers starting from $12$.
The next consecutive number is $16$.

$$16^2=256$$

Thus, the next number in the series is $256$.