It's a big number. If translated into litres of water it would fill eight and a half Olympic swimming pools and in minutes it would be almost 40 years.
Twenty-one million is also the number of views on a video of Edmonton model Travis DesLaurier working out with his cat.
"It's a shock when it happens, you really don't think it can happen to you, just like anything in life," said DesLaurier. "When it does, it really blows your mind. You really can't comprehend it."
The insanity started last week when DesLaurier posted an 18-second tongue-in-cheek video of himself working out with Jacob, his cat. The video ends with a shot of him wiping his brow with the cat's tail and blowing a kiss into the camera.
It immediately went viral.
Since then, life has been a whirlwind for the 31-year-old and his orange tabby. The photogenic duo have been featured in Cosmopolitan, Buzzfeed, La Repubblica and many more media outlets.
"You would be amazed how many times I'm asked to take my shirt off in interviews," laughed DesLaurier when visiting Edmonton AM Thursday.
'I don't want to do just the shirtless thing but it's a good start.' - Travis DesLaurier
While he kept his shirt on during the interview, DesLaurier did say he can't overlook the impact his looks have on the popularity of his videos. But he is adamant he's more than a pretty face.
"We all know that in today's world, sex does sell and when you have that bit of sexuality you can certainly push the envelope," he said. "But a lot of it is strategic too, there are a lot of people that do the same thing that don't go anywhere with it."
"I don't want to do just the shirtless thing, but it's a good start."
Perhaps the most genius thing about DesLaurier's video is the fact he mixed sex appeal with cats. As we all know the internet is, shall we say, rather fond of cats.
"Worldwide it probably has over 100 million views right now," he said. "People love cat videos, that's not a joke. That's a very strategic marketing strategy."
A little more than a year ago, DesLaurier started actively attempting to become a celebrity through social media.
'People love cat videos, that's not a joke. That's a very strategic marketing strategy.' - Travis DesLaurier
"I saw people getting quite famous from using this medium. I wasn't really happy with life and thought why couldn't I do that," said DesLaurier.
"It's a major powerful tool that can lead you down extraordinary avenues."
Right now, DesLaurier said he is attempting to make a go out of a modeling and acting career but his life is so crazy he's making a point not to create any concrete plans.
"I really don't know and that's the most exciting part of my life right now," he said. "I used to have all these answers and now I don't, I'm just letting the wind take me."