# 154

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## Number

$154$ (one hundred and fifty-four) is:

$2 \times 7 \times 11$

The $12$th sphenic number after $30$, $42$, $66$, $70$, $78$, $102$, $105$, $110$, $114$, $130$, $138$:
$154 = 2 \times 7 \times 11$

The $21$st nontotient:
$\nexists m \in \Z_{>0}: \phi \left({m}\right) = 154$
where $\phi \left({m}\right)$ denotes the Euler $\phi$ function

The $14$th noncototient after $10$, $26$, $34$, $50$, $52$, $58$, $86$, $100$, $116$, $122$, $130$, $134$, $146$:
$\nexists m \in \Z_{>0}: m - \phi \left({m}\right) = 154$
where $\phi \left({m}\right)$ denotes the Euler $\phi$ function

The $6$th term of Göbel's sequence after $1$, $2$, $3$, $5$, $10$, $28$:
$154 = \left({1 + 1^2 + 2^2 + 3^2 + 5^2 + 10^2 + 28^2}\right) / 6$

The $30$th positive integer $n$ such that no factorial of an integer can end with $n$ zeroes.

The $12$th integer $m$ such that $m! + 1$ (its factorial plus $1$) is prime:
$0$, $1$, $2$, $3$, $11$, $27$, $37$, $41$, $73$, $77$, $116$, $154$