A Deleting a purchase account would automatically terminate all subscriptions and, as a result, would probably also terminate the Prime Membership.
Below are some links to pages that might be helpful, but please contact the respective stores for more information.

App Store：https://support.apple.com/102559
GooglePlay Store：https://support.google.com/accounts/answer/32046

Also, please note that deleting an authorized account other than an Apple Account (ibisAccount, X, Facebook) will not cancel your subscription.

The difference between a purchased account and an authenticated account is explained in the
“Synchronizing the artworks on your device with Cloud Storage” section of the Tutorials.