New posts in Repunit Numbers

Can $7$ be the smallest prime factor of a repunit?

Find the $1000$th digit after the decimal point of $\sqrt{n},$ where $n=\underbrace{11\dots1}_{1998 \text{ 1's}}$

Is $1111111111111111111111111111111111111111111111111111111$ ($55$ $1$'s) a composite number?

The sequence of integers $1, 11, 111, 1111, \ldots$ have two elements whose difference is divisible by $2017$

Prove that 17 divides 1111111111111111 (16 1's) and doesn't divide 11111111

What is $\underbrace{555\cdots555}_{1000\ \text{times}} \ \text{mod} \ 7$ without a calculator

Primes dividing $11, 111, 1111, ...$

Why do repunit primes have only a prime number of consecutive $1$s?

When is the number $11111\cdots1$ a prime number?

Prove that none of $\{11, 111, 1111,\dots \}$ is the perfect square of an integer