2278

Number
$2278$ (two thousand, two hundred and seventy-eight) is:
 * $2 \times 17 \times 67$


 * The $34$th hexagonal number after $1$, $6$, $15$, $28$, $45$, $66$, $91$, $\ldots$, $703$, $780$, $861$, $946$, $1035$, $1225$, $1326$, $1431$, $1540$, $1653$, $1770$, $1891$, $2016$, $2145$:
 * $2278 = \displaystyle \sum_{k \mathop = 1}^{34} \left({4 k - 3}\right) = 34 \left({2 \times 34 - 1}\right)$