Q: Is 21,385 a Prime Number?

A: No, 21,385 is not a prime number.

Why is 21,385 not a prime number?

A prime number is a natural number, greater than one, that can only be divided by 1 and itself.

The number 21385 can be evenly divided by 1 5 7 13 35 47 65 91 235 329 455 611 1,645 3,055 4,277 and 21,385, with no remainder.

Since 21,385 cannot be divided by just 1 and 21,385, it is not a prime number.

Number	21,383	21,384	21,386	21,387
Prime?	yes	no	no	no

All positive natural numbers are either a prime number or a composite number (except the number 1, which is neither).

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