Find the dissimilar number.
$78,104,130,156,178$

Let's check the divisibility or table pattern of the given numbers:
* $78=26\times 3$ (or $13\times 6$)
* $104=26\times 4$ (or $13\times 8$)
* $130=26\times 5$ (or $13\times 10$)
* $156=26\times 6$ (or $13\times 12$)
* All the above numbers ($78,104,130,156$) are exact multiples of $26$ (and $13$).

Now let's check $178$:

* $178=26\times \mathrm{6.846...}$ (Not perfectly divisible by $26$ or $13$).
Therefore, $178$ is the odd/dissimilar number.