1080

Number
$1080$ (one thousand and eighty) is:


 * $2^3 \times 3^3 \times 5$


 * The $27$th pentagonal number after $1$, $5$, $12$, $22$, $35$, $\ldots$, $477$, $532$, $590$, $651$, $715$, $782$, $852$, $925$, $1001$:
 * $1080 = \ds \sum_{k \mathop = 1}^{27} \paren {3 k - 2} = \dfrac {27 \paren {3 \times 27 - 1} } 2$


 * The $53$rd generalized pentagonal number after $1$, $2$, $5$, $7$, $12$, $15$, $\ldots$, $610$, $651$, $672$, $715$, $737$, $782$, $805$, $852$, $876$, $925$, $950$, $1001$, $1027$:
 * $1080 = \ds \sum_{k \mathop = 1}^{27} \paren {3 k - 2} = \dfrac {27 \paren {3 \times 27 - 1} } 2$