
Ask HN: Why does Google fail to judge whether X is prime - lnyan
If you type &quot;is 1000000007 prime&quot; into google, you&#x27;ll find that google suggests that 1000000007 is not a prime. 
See https:&#x2F;&#x2F;i.imgur.com&#x2F;ZWyoxLx.png<p>However, 1000000007 is a well-known prime used in many programming competitions or online judges.<p>The same thing will happen if you type &quot;is 15485863 prime&quot; into google. (which is the 1000000th prime)
See https:&#x2F;&#x2F;i.imgur.com&#x2F;vrCKqL7.png<p>Perhaps, starting with 1299709 (the 100000th prime), the answers might be all wrong.<p>It seems that determining whether an input number is prime should not go wrong easily. 
So, why does google fail to do that?
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PaulHoule
I think Wolfram Alpha would try to parse the query and turn it into a
statement like:

PrimeQ[1000000007]

[https://reference.wolfram.com/language/ref/PrimeQ.html](https://reference.wolfram.com/language/ref/PrimeQ.html)

I think Google is not doing that, instead they are scraping the web for spam
sites that have automatically generated answers such as

[https://bloodpressureok.com/reading/172-over-67/](https://bloodpressureok.com/reading/172-over-67/)

which is bound to be less reliable.

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Spooky23
That was a bing marketing thing for awhile. Bing would answer certain
questions from authoritative sources.

Google has an inconsistent approach.

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lnyan
Here are the screenshots used in the post 1000000007:
[https://i.imgur.com/ZWyoxLx.png](https://i.imgur.com/ZWyoxLx.png) 15485863:
[https://i.imgur.com/vrCKqL7.png](https://i.imgur.com/vrCKqL7.png)

