1477

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Number

$1477$ (one thousand, four hundred and seventy-seven) is:

$7 \times 211$

The $18$th integer $m$ such that $m! + 1$ (its factorial plus $1$) is prime:

$0$, $1$, $2$, $3$, $11$, $27$, $37$, $41$, $73$, $77$, $116$, $154$, $320$, $340$, $399$, $427$, $872$, $1477$

It was checked that it is a prime number using the "Alpertron" Integer factorisation calculator on $6$th March $2022$.

This took approximately $20$ seconds.

Also see

• Previous  ... Next: Sequence of Integers whose Factorial plus 1 is Prime

Sources

• 1997: David Wells: Curious and Interesting Numbers (2nd ed.) ... (previous) ... (next): $1477$
• 1997: David Wells: Curious and Interesting Numbers (2nd ed.) ... (previous) ... (next): $1477! + 1$