643

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Number

$643$ (six hundred and forty-three) is:

The $117$th prime number

The larger of the $29$th pair of twin primes:

$643 - 641 = 2$

The $38$th left-truncatable prime after $2$, $3$, $5$, $7$, $\ldots$, $443$, $467$, $523$, $547$, $613$, $617$

Also see

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