The figure includes two refugees, who will participate under the International Paralympic Athletes flag, the International Paralympic Committee (IPC) said on Wednesday, Xinhua news agency reported.
Of the 4,432 athletes registered for the September 7-18 Games, a record 1,621 are women - 12 per cent more than London four years ago and more than double the number that participated in Atlanta 20 years ago.
The overall number of athletes in Rio eclipses the 4,302 participants that took part in London and the 3,951 who were registered in Beijing in 2008.
The high participation level comes despite the late withdrawals of Comoros and Liberia, and the absence of Russia.
(Full list of Indian athletes at Rio 2016 Paralympics)
IPC president Philip Craven said organisers had overcome many obstacles, such as budget cuts and slow early ticket sales amid Brazil's worst recession in decades.
"Two weeks ago I said we faced unprecedented circumstances and since then we've seen unprecedented teamwork," Craven told a news conference.
"The feeling coming out of the athletes village is that athletes are happy. The thing to remember is athletes perform best when they are happy and I only saw happy athletes in the village, and that's all right for me."
Since the Olympic Games closing ceremony on August 21, ticket sales have risen from 300,000 to almost 1.7 million, Craven said.
Organisers are now hoping the to overtake the 2.4 million tickets sold at the Beijing 2008 Games.
"These are going to be the people's Games. You cannot come to a more passionate country for sport, but you've got to engage with the hearts," Craven said.
Craven said a record 1,500 athletes would be tested for doping during the Rio Paralympics.
The Games will be broadcast to 154 countries and regions - 39 more than in London.