Python 3, (削除) 86 (削除ここまで) 78 bytes

Saved 8 bytes thanks to ovs!!!

lambda s:all(n%i for n in(len(s),sum(ord(c)&31for c in s))for i in range(2,n))

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Returns True or False.

Python 3, (削除) 86 (削除ここまで) (削除) 78 (削除ここまで) 87 bytes

Saved 8 bytes thanks to ovs!!!
Added 9 bytes to fix a bug kindly pointed out by Robin Ryder .

lambda s:~-len(s)*all(n%i for n in(len(s),sum(ord(c)&31for c in s))for i in range(2,n))

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Returns a truthy or falsey value.

Python 3, (削除) 86 (削除ここまで) 78 bytes

Saved 8 bytes thanks to ovs!!!

lambda s:all(n%i for n in(len(s),sum(ord(c)&31for c in s))for i in range(2,n))

Try it online!

Python 3, (削除) 86 (削除ここまで) 78 bytes

Saved 8 bytes thanks to ovs!!!

lambda s:all(n%i for n in(len(s),sum(ord(c)&31for c in s))for i in range(2,n))

Try it online!

Returns True or False.

Python 3, 86 bytes

lambda s:p(len(s))&p(sum(ord(c)&31for c in s))
p=lambda n:all(n%i for i in range(2,n))

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Python 3, (削除) 86 (削除ここまで) 78 bytes

Saved 8 bytes thanks to ovs !!!

lambda s:all(n%i for n in(len(s),sum(ord(c)&31for c in s))for i in range(2,n))

Try it online!