590

Number
$590$ (five hundred and ninety) is:


 * $2 \times 5 \times 59$


 * The $20$th pentagonal number after $1$, $5$, $12$, $22$, $35$, $51$, $70$, $92$, $117$, $145$, $176$, $210$, $247$, $287$, $330$, $330$, $376$, $425$, $477$, $532$:
 * $590 = \ds \sum_{k \mathop = 1}^{20} \paren {3 k - 2} = \dfrac {20 \paren {3 \times 20 - 1} } 2$


 * The $39$th generalized pentagonal number after $1$, $2$, $5$, $7$, $12$, $15$, $\ldots$, $392$, $425$, $442$, $477$, $495$, $532$, $551$:
 * $590 = \ds \sum_{k \mathop = 1}^{20} \paren {3 k - 2} = \dfrac {20 \paren {3 \times 20 - 1} } 2$