Arsene Wenger's side have not lost a Premier League match since January 2012 when the pair have both finished a game, with the defensive duo notching up 23 wins in 32 outings in that time.
The Germany international believes it is an incredible statistic, one that proves how well the two work together.
"It (the statistic) sounds not real to me," Mertesacker told the club's official website.
"When I first heard it, it sounded very weird. It's a good statistic but we have to build on that.
"I think we have shown a lot of people who criticised us a lot over the last two and a half years that we know each other much better now.
"We complement each other well, so it looks like that's a good partnership."
Mertesacker went on to extoll the virtues of Koscielny as Arsenal look to end a trophy drought that stretches back to the FA Cup final win over Manchester United in 2005.
"I've played with many good centre-backs with different qualities," he said.
"But Laurent, he's one of the quickest players I've ever played with, one of the most mobile players, and he anticipates well a lot of balls so he has real strengths to be a good partner.
"For me it's easy to play alongside him. We both take advantages from each other so that is the main key I think."
