137,438,953,471/Historical Note

Historical Note on $137 \, 438 \, 953 \, 471$

$137 \, 438 \, 953 \, 471$ was the $3$rd Mersenne number to be demonstrated composite.

This was done in $1640$ by Pierre de Fermat, who demonstrated it had $223$ as a divisor.

It is in fact the $4$th Mersenne number in sequence to be composite.

However, the status of the $3$rd such composite Mersenne number, $536 \, 870 \, 911$, was not established until Leonhard Paul Euler's work in $1732$.

Sources

• 1919: Leonard Eugene Dickson: History of the Theory of Numbers: Volume $\text { I }$ ... (previous) ... (next): Preface