512

Number
$512$ (five hundred and twelve) is:
 * $2^9$


 * In binary:
 * $1 \, 000 \, 000 \, 000$


 * In octal:
 * $1 \, 000$


 * The $8$th cube number after $1$, $8$, $27$, $64$, $125$, $216$, $343$:
 * $512 = 8 \times 8 \times 8$


 * The $10$th almost perfect number after $1$, $2$, $4$, $8$, $16$, $32$, $64$, $128$, $256$:
 * $\sigma \left({512}\right) = 1023 = 2 \times 512 - 1$


 * The index (after $2$, $3$, $6$, $30$, $75$, $81$, $115$, $123$, $249$, $362$, $384$, $462$) of the $13$th Woodall prime:
 * $512 \times 2^{512} - 1$


 * The $25$th positive integer after $64$, $96$, $128$, $144$, $\ldots$, $384$, $400$, $416$, $432$, $448$, $480$, $504$ with $6$ or more prime factors:
 * $512 = 2 \times 2 \times 2 \times 2 \times 2 \times 2 \left({\times \, 2 \times 2 \times 2}\right)$


 * The $9$th positive integer after $128$, $192$, $256$, $320$, $384$, $432$, $448$, $480$ with $7$ or more prime factors:
 * $512 = 2 \times 2 \times 2 \times 2 \times 2 \times 2 \times 2 \left({\times \, 2 \times 2}\right)$


 * The $14$th positive integer after $200$, $202$, $204$, $205$, $206$, $208$, $320$, $322$, $324$, $325$, $326$, $328$, $510$ that cannot be made into a prime number by changing just $1$ digit