3828

Number
$3828$ (three thousand, eight hundred and twenty-eight) is:


 * $2^2 \times 3 \times 11 \times 29$


 * The $87$th triangular number after $1$, $3$, $6$, $10$, $15$, $\ldots$, $3240$, $3321$, $3403$, $3486$, $3570$, $3655$, $3741$:
 * $3828 = \displaystyle \sum_{k \mathop = 1}^{87} k = \dfrac {87 \times \left({87 + 1}\right)} 2$


 * The $44$th hexagonal number after $1$, $6$, $15$, $28$, $45$, $66$, $91$, $\ldots$, $2145$, $2278$, $2415$, $2556$, $2701$, $2850$, $3003$, $3160$, $3321$, $3486$, $3655$:
 * $3828 = \displaystyle \sum_{k \mathop = 1}^{44} \left({4 k - 3}\right) = 44 \left({2 \times 44 - 1}\right)$