Finding $10^{1001}(\text{mod} \ 1001)$
4972
Mod of numbers with large exponents [modular order reduction]
28330
Finding x in $a^{x} \bmod  b = c$ when values a,b, and c are known?
38727
Modular Exponentiation and Primes
133430
How to solve $x^x=100$?
156510
How to compute $2^{\text{some huge power}}$
139776
Divisibility tests and remainder mod $9,11,99,101,999,1001\,$ (casting out nines and elevens)
68960
How to solve $ 13x \equiv 1 ~ (\text{mod} ~ 17) $?
23153
$\bmod p\!:\ x^2\equiv 1\iff x\equiv \pm1\ $ for prime $p$
40896
What is the largest positive $n$ for which $n^3+100$ is divisible by $n+10$
49649
How can I find out whether a number is a quadratic residue in a large modulo?
8784
modulo version of the quadratic formula and Euler's criterion
147470
Divisibility of Consecutive Powers of 10
119219
What does Mod^(1,0) mean in mathematica output
67312
How to find the last digit of $3^{1000}$?
58803
${n \choose k} \bmod m$ using Chinese remainder theorem?
72406
Last two digits of $2^{1000}$ via Chinese Remainder Theorem?
143754
Finding the solution of the congruence $4x\equiv16\pmod{26}$