Why was 1 considered as prime years ago?
48587
Why is $1$ not a prime number?
2802
If $2^n+1$ is prime, why must $n$ be a power of $2$?
101987
Is there possibly a largest prime number?
23932
Why do repunit primes have only a prime number of consecutive $1$s?
8740
What is so special about Prime?
126945
checking if a number is a prime
28380
What is the definition of prime number?
68169
Why dec 31 2010 returns 1 as week of year?
11440
When is the number $11111\cdots1$ a prime number?
38458
Why was The One Ring "precious"?
54547
Prove this number must be a prime number or 1.
87780
Is the ideal $(2,X+1)\subset\Bbb{Z}[X]$ prime, maximal or neither?
126471
At least one prime between $\sqrt{n}$ and $n$?
68155
Explanation why $\frac{(x-1)!-(x-1)}x$ is always an integer for prime $x$
45793
How do you prove a number is prime?
151701
Does there exist an $a_0$ such that the sequence $a_{n+1} = 2a_n + 1$ is prime for all $n \ge 0$?
99890
Primes with digits only 1