Infinite sum of integers

You have probably seen the following video that shows that:

1 +2 + 3 + 4 + ... = -1/12

Yes; the sum of all integers from 1 to infinity it is not only finite, it is also equal to a small value, which is negative!

If you haven't yet, do watch it. Then, for clarification, you can read the links below:

• Wikipedia
• https://plus.maths.org/content/infinity-or-just-112
• Scientific American
• After Sunclipse
• What's New