228

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Number

$228$ (two hundred and twenty-eight) is:

$2^2 \times 3 \times 19$

The $2$nd integer after $3$ whose square is the sum of $2$ coprime cubes:

$228^2 = 37^3 + 11^3$

The $3$rd element of the $2$nd set of $4$ positive integers which form an arithmetic sequence which all have the same Euler $\phi$ value:

$\map \phi {216} = \map \phi {222} = \map \phi {228} = \map \phi {234} = 72$

The $14$th of the $17$ positive integers for which the value of the Euler $\phi$ function is $72$:

$73$, $91$, $95$, $111$, $117$, $135$, $146$, $148$, $152$, $182$, $190$, $216$, $222$, $228$, $234$, $252$, $270$

Also see

• Previous  ... Next: Squares equal to Sum of 2 Cubes
• Previous  ... Next: 4 Positive Integers in Arithmetic Sequence which have Same Euler Phi Value
• Previous  ... Next: Numbers with Euler Phi Value of 72

Sources

• 1997: David Wells: Curious and Interesting Numbers (2nd ed.) ... (previous) ... (next): $51,984$