Base 10 theorem in number theory
3128
Why $9$ & $11$ are special in divisibility tests using decimal digit sums? (casting out nines & elevens)
111764
A definition of Conway base-$13$ function
81267
A simple doubt in number theory problem.
26588
Prove by induction that $10^n -1$ is divisible by 11 for every even natural number
140006
Are there infinitely many primes and non primes of the form $10^n+1$?
568
Consider a set $A$ of $10$ integers, $A = \{a_1,a_2, \ldots ,a_{10}\}$. Prove that there is at least one subset of $A$ whose sum is divisible by $10$.
147470
Divisibility of Consecutive Powers of 10
68233
Fermat's little theorem's proof for a negative integer
43940
Showing that $n$ is pseudoprime to the base $a$
8710
Bounds for $n$-th prime
147485
A conjecture about numbers of the form $10^{m}(2^{k}−1)+2^{k-1}−1$, where $m$ is the number of decimal digits of $ 2^{k-1}$.
90537
Converse of Fermat's Little Theorem.
70523
Proving that $x^4 - 10x^2 + 1$ is not irreducible over $\mathbb{Z}_p$ for any prime $p$.
105225
Number Theory: Complete set of residues modulo $n$
146867
Combinatorial Proof Of A Number Theory Theorem--Confusion
49711
Prove that $6p$ is always a divisor of $ab^{p} - ba^{p}$.
128634
Doubt related to a theorem in congruences of Chapter 5 of Apostol Introduction to analytic number theory