727

Number
$727$ (seven hundred and twenty-seven) is:


 * The $129$th prime number


 * The $3$rd integer after $428$, $573$ whose square has a decimal representation consisting of the concatenation of $2$ consecutive increasing integers:
 * $727^2 = 528 \, 529$


 * The $4$th integer after $91$, $428$, $573$ whose square has a decimal representation consisting of the concatenation of $2$ consecutive integers:
 * $727^2 = 528 \, 529$


 * The larger of the $10$th pair of primes whose prime gap is $8$:
 * $727 - 719 = 8$


 * The $15$th palindromic prime:
 * $2$, $3$, $5$, $7$, $11$, $101$, $131$, $151$, $181$, $191$, $313$, $353$, $373$, $383$, $727$, $\ldots$


 * The $15$th palindromic lucky number:
 * $1$, $3$, $7$, $9$, $33$, $99$, $111$, $141$, $151$, $171$, $303$, $393$, $535$, $717$, $727$, $\ldots$


 * The $47$th long period prime after $7$, $17$, $19$, $23$, $29$, $\ldots$, $491$, $499$, $503$, $509$, $541$, $571$, $577$, $593$, $619$, $647$, $659$, $701$, $709$

Also see