153

Number
$153$ (one hundred and fifty-three) is:


 * $3^2 \times 17$


 * The $17$th triangular number after $1, 3, 6, 10, 15, 21, 28, 36, 45, 55, 66, 78, 91, 105, 120, 136$:
 * $153 = \displaystyle \sum_{k \mathop = 1}^{17} k = \dfrac {17 \times \left({17 + 1}\right)} 2$


 * The $9$th hexagonal number after $1, 6, 15, 28, 45, 66, 91, 120$:
 * $153 = 1 + 5 + 9 + 13 + 17 + 21 + 25 + 29 + 33 = 9 \left({2 \times 9 - 1}\right)$


 * The sum of the first $5$ factorials:
 * $153 = 1! + 2! + 3! + 4! + 5!$


 * The $10$th pluperfect digital invariant after $1, 2, 3, 4, 5, 6, 7, 8, 9$, and the $1$st non-trivial one:
 * $1^3 + 5^3 + 3^3 = 1 + 125 + 27 = 153$

Also see

 * Repeated Sum of Cubes of Digits of Multiple of 3