Efficient way to solve $31^6 \mod 189$ without using any external devices.
360
Modular exponentiation by hand ($a^b\bmod c$)
21874
Solve $x^3+x \equiv 1 \pmod p$
56974
Determining the missing digits of $15! \equiv 1\square0767436\square000$ without actually calculating the factorial
84879
Solving infinite sums with primes.
69121
Fastest way to calculate $e^x$ up to arbitrary number of decimals?
36713
Solving multiple congruences by CRT = Chinese Remainder Theorem
55984
How can I find the answer to $\varphi(2^{400} + 2)$?
11335
Proving Binomial Identity without calculus
81058
Evaluate $6^{433} \pmod {21}$ and a proving question
55049
How to find the inverse modulo $m$?
155012
Solving quadratic equations in modular arithmetic
144067
calculating $a^b \!\mod c$
978
Solving $ax \equiv c \pmod b$ efficiently when $a,b$ are not coprime
100512
Is there a way to systematically calculate the public exponent $e$ in RSA?
102860
solve $3x^2 + 6x +1 \equiv 0 \pmod {19}$
99037
Prove the sum of all numbers that do not have a multiplicative inverse mod $n$
107848
Finding the remainder of $\overbrace{11\ldots1}^{123 \text{ times}}$ divided by $271$