According to WorldoMeters, a site that shows the current world population by the seconds, Nigeria’s population hits 177,236,824 as at the moment of writing this. Worldometers gives real time world statistics which means, the number (population number) can change any time. To be on a safe side, I’ll leave Nigeria’s population as 177 million.
With this population, Nigeria is ranked as 7th largest country by population. The other top 20 largest countries by population are as shown in the image/screenshot below.
The real time statistical ranking is based on the algorithm used on the site. You can find more real time statistics on WorldoMeters