Say what you will about the actual year 2016 but as a number it sure is amazing. It is a triangular number which means that you can arrange 2016 dots in the shape of an equilateral triangle. Here is an example for the triangular number 10:
Observe that each layer of the triangle has one less dot. In other words, 10 is a triangular number because 5+4+3+2+1=10. Similarly, for 2016 we have that 63+62+...+4+3+2+1=2016. Besides, being a triangular number it also has the omnious property that 666+666+666+6+6+6=2016[1].
Last year it was 2017, which is a prime example of a prime number! This wonderfull prime can be written as the sum of two squared number: 442+92=2017. Remarkably, these are the only possible squared numbers whose sum is 2017. This is a consequence of Fermat's Theorem on sums of two squares (Here is the Theorem for the fans).
So what kind of secrets does 2018 have? Well it is not triangular and not prime. In actual fact, 2018 is a semi-prime which is the product of two primes. In this case 2 x 1009= 2018. The number 2018 is the 579th semi-prime which does not make it a rare property [2]. The only nice property of 2018 I could find was the following [3]:
Well hopefully the fact that 2018 is not such an interesting number will say something about the politcal events of this year :)
Sources
[1] Vsauce post
[2] https://prime-numbers.info/number/579th-semiprime
[3] https://yutsumura.com/mathematics-about-the-number-2018/
Top figure found here
The remaining figures were made using Inkscape and math text was made using Quicklatex. Both are free to use!
Further reading
If you want to find out more about triangular numbers click here for the wiki page.
Thank you!
Thanks for being so kind to read my post. You are awesome! Please follow me if you enjoyed it. If you have any questions just post them below and I will answer them. Or if you might have a nice topic you want me to cover also let me know below :o)