Is $\pi$ even or odd?
107105
Is an irrational number odd or even?
21383
Can every even integer be expressed as the difference of two primes?
86428
Can we show that the decimal expansion of $\pi$ doesn't occur in the decimal expansion of the Champernowne constant?
139411
Finding $\pi$ factorial
147363
Is $\large \frac {\pi}{e}$ rational, irrational, or trandescendal?
44182
Proving that an integer is even if and only if it is not odd
68824
Show that $\frac{(3^{77}-1)}{2}$ is odd and composite
23705
Does $\pi$ contain all possible number combinations?
5679
Why is $2\pi i \neq 0?$
105423
Why doesn't every integral from 0 to $2\pi$ equal zero?
50038
Proving that $e^\pi=e^{-\pi}$
66703
Show that $8 \mid (a^2-b^2)$ for $a$ and $b$ both odd
21152
Exactly half of the elements of $\mathcal{P}(A)$ are odd-sized
52542
For which odd positive integer $n$ , is it true that $-1$ is not a positive power of $2$ modulo $n$?
66872
Exact values of $\cos(2\pi/7)$ and $\sin(2\pi/7)$
72054
Show that $\deg f$ is even when $n$ is odd.
75731
Significance of $\pi$ in physics