# 69

Many of you have already asked me why $69$ is in all the testcases of my problems and why I use this insanely beautiful number everywhere. Thats because $69$ is my most favorite number and there are various reasons for that. One has been described by Grant in this video and I will describe a few others:

• It is a semi-prime number, that is a product of two primes. $69 = 3 \cdot 23$. Nice!
• The number $69$ can be inverted and still seen the same. Nice!
• The angel number $69$ means closure. If you see this number more often, it means something is about to happen. I am not kidding, try searching online.
• In most calculators, the highest factorial of any numbe that can be calculated is $69$. Nice!
• $69$ is also the only integer where its square and its cube used up all digits from $0-9$ and each exactly once! $69^2 = 4761$ and $69^3 = 328509$. Nice!
• If you reverse it you will get a nasty number and that is 96. A nasty number is a positive integer having at least four different factors such that the difference between one pair of factors equals the sum of another pair of factors. 96 is nasty because $24 – 4 = 12 + 8$. So don’t try to reverse it you nasty mf.
• Also, according to various sources, this is the only number when you see it, it is your duty or I would say it is a must to say the word “nice”. Otherwise it will bring you bad luck.

So, yeah.

Nice!