1596

Number
$1596$ (one thousand, five hundred and ninety-six) is:
 * $2^2 \times 3 \times 7 \times 19$


 * The $56$th triangular number after $1$, $3$, $6$, $10$, $15$, $\ldots$, $990$, $1035$, $1081$, $1128$, $1176$, $1225$, $1275$, $1326$, $1378$, $1431$, $1485$, $1540$:
 * $1596 = \ds \sum_{k \mathop = 1}^{56} k = \dfrac {56 \times \paren {56 + 1} } 2$