1855

Number
$1855$ (one thousand, eight hundred and fifty-five) is:
 * $3 \times 5 \times 53$


 * The $35$th second pentagonal number after $2$, $7$, $15$, $26$, $\ldots$, $1107$, $1190$, $1276$, $1365$, $1457$, $1552$, $1650$, $1751$:
 * $1855 = \dfrac {35 \left({3 \times 35 + 1}\right)} 2$


 * The $70$th generalized pentagonal number after $1$, $2$, $5$, $7$, $12$, $15$, $\ldots$, $1335$, $1365$, $1426$, $1457$, $1520$, $1552$, $1617$, $1650$, $1717$, $1751$, $1820$:
 * $1855 = \dfrac {35 \left({3 \times 35 + 1}\right)} 2$