Indestructible creatures also ignore deathtouch. Normally, a creature is destroyed if it takes damage from a creature with deathtouch. But since indestructible creatures can't be destroyed, they're immune.

Does Deathtouch override indestructible?

Does desthtouch defeat indestructible? No, deathtouch causes "lethal damage" to creatures, indestructible creatures cannot be killed by "lethal damage". 702.2a Deathtouch is a static ability.

What kills indestructible?

A creature with indestructible can die as a result of anything that is not damage (Lightning Bolt) and does not explicitly use the word 'destroy' (Doom Blade). And of course, they can be exiled, returned to their owner's hand, or put back into their owner's library.