Passage: Douglass has three other channels, dubbed jackisanerd, featuredfridays and SHUTUPDENNIS. He uses his secondary channel jackisanerd mainly for video blogs. It has earned over 51 million video views and over 562,000 subscribers as of September 4, 2018. Across his four channels, he has over 1,000 videos as of February 2017. featuredfridays was originally a series on Douglass' main channel before having its own channel for a brief period. The channel has been inactive since March 11, 2011. The channel SHUTUPDENNIS has also been deemed inactive.On November 20, 2015, Douglass started a new series on the Regal Cinemas YouTube channel named Jack Talks Trailers, in which he gives a brief recap of new film trailers that are released within the past week. At the end of each episode, Douglass reads the opinions of people's thoughts about a specific trailer shown in the episode.

Question: How many channels does douglass have?
three other channels