You are right. I was off by few million, according to below stats counter. Note that any count is an estimation due to the decentralized nature of the network and instances not counted. I've seen other higher numbers too.
https://mastodont.cat/@fediverse/110191027067688818
servers: 21,583 (-17, max: 21,600) users: 8,990,211 (-69,061, max: 9,059,272) MAU: 1,469,800 (-8,596, max: 2,444,236)