According to South Korean outlet News1 the Samsung Galaxy Note 4 has hit 4.5 million sales globally about a month after its launch (it launched September 26). That's a little lower than the 5 million units its predecessor sold in its first month, but the Galaxy Note 3 got a wider release initially.
The Galaxy Note 4 started off in South Korea and China and has been expanding its availability ever since. It started selling in the US only recently. The flagship phablet also experienced some delays in markets like the UK and India where sales started a week ago. As for China, Samsung rolled out the dual-SIM versions only a couple of days ago.
The 4.5 million number doesn't seem to include the Galaxy Note Edge, Note 4's sibling with a two-sided screen, which is only now going on sale and in just a few markets.
The Galaxy Note 4 may have hit a few bumps on the way out but Samsung needed a best seller as its Q3 earnings declined.