The data come from AJS (Arhiv javnih skupova), an independent observer consisting of journalists and intellectuals who usually calculate the number of participants in demonstrations.
The number thus differs significantly from that announced by Serbia's National Police Chief Dragan Vasiljevic on Saturday, which was around 34,300.
If AJS figures are correct, it is the second largest demonstration in Serbia since the mass protests against then-leader Slobodan Milosevic in 2000.
In March last year, between 275,000 and 325,000 people participated in mass demonstrations against corruption and the country's government, led by President Aleksandar Vucic.
