proove a 3 digit block is divisible by 37
3128
Why $9$ & $11$ are special in divisibility tests using decimal digit sums? (casting out nines & elevens)
48605
Distinct digits in a combination of 6 digits
91921
Divisibility of $n\cdot2^n+1$ by 3.
124890
Divisibility within a block of natural numbers
49967
Find the last two digits of $ 7^{81} ?$
48053
Show that 13 divides $2^{70}+3^{70}$
144801
$1-\frac{1}{2}+\frac{1}{3}-\frac{1}{4}+\frac{1}{5}-\dots+\frac{1}{1331}=\frac{p}{q}$; is $p$ divisible by $1997$?
49687
Show that the number 9 divides the number $ m$ if and only if the sum of the digits of the number $ m $ is divisible by 9.
149961
Two digit numbers
122207
Use the Division Algorithm to show the square of any integer is in the form $3k$ or $3k+1$
83910
Integer part of $\sqrt[3]{24+\sqrt[3]{24+\sqrt[3]{24+\cdots}}}$
16176
Primitive Pythagorean triple divisible by 3
125210
proof: primitive pythagorean triple, a or b has to be divisible by 3
148703
Permutations with repeating digits
49626
Find the last two digits of $33^{100}$
34784
Is a number meeting these conditions divisible by forty-nine?
99890
Primes with digits only 1