memberCount property
memberCount Number of members in the supergroup or channel; 0 if unknown. Currently, it is guaranteed to be known only if the supergroup or channel was received. through searchPublicChats, searchChatsNearby, getInactiveSupergroupChats, getSuitableDiscussionChats, getGroupsInCommon, getUserPrivacySettingRules, or in chatFolderInviteLinkInfo.missing_chat_ids
Implementation
final int memberCount;