1234567891 and 123456791 easy to remember primes for testing some things in number theory.
Also 31, 331, 3331, 33331, 333331, 3333331, 33333331 are all prime.
Writing "pretty" math (two dimensional) is easier to read and grasp than LaTex (one dimensional).
LaTex is like painting on many strips of paper and then stacking them to see what picture they make.
The fourth repunit prime is huge
And no one knows how many of them there are!
In mathematics, you don't understand things. You just get used to them.
Of course that result can be rigorously obtained, but who cares?
Combinatorics is Algebra and Algebra is Combinatorics.
3691 the only primenumber I have noticed till now in a car's number plate
'And fun? If maths is fun, then getting a tooth extraction is fun. A viral infection is fun. Rabies shots are fun.'
'God exists because Mathematics is consistent, and the devil exists because we cannot prove it'
'Humanity is still kept intact. It remains within.' -Alokananda