IS 97 A PRIME NUMBER?

A prime number has only two factors: one and itself. To find out if a number is prime or not. We need to find its prime factorization. For example 2•2•2 is 8. So 8 is not prime. 2 is prime. 3 is prime, and so on. The prime numbers in any prime factorization, can not exceed the square root of the number.

Category:

Education

Tags:

• Prime
• numbers
• divisibility
• composite
• number
• primes
• division
• prime
• factorization
• square
• root

[jwm239]

...a repetend is that cluster of digits

which is repeated in a "repeating decimal." E.g., 1/7 = .142857142857142857...

hence the repetend is 142857.

[HAMLETOIS]

How can one explain 1/2, 1/3, 1/5/, Here the repeatends are weird! don't you think?

[jwm239]

...the repetend of 1/97 is of maximum

length (96), and only primes will

have that property as far as I know.

E.g., if the repetend of 1/P has

length P-1, then P is prime.

[HAMLETOIS]

What's a repetend?

[SolarPowerPlant13]

LOL 2590 views for a video about a prime number!

[VEVOdubstep]

If you're going to make a video on prime numbers, I would suggest showing some techniques of proving Mersenne numbers prime, instead of a trivial example of Eratosthene's seive.

[weslop123456789]

I'm in 6th grade and learning about primes...As soon as I saw this video I clicked it. I knew 97 was prime. :)

[759009946576]

@HAMLETOIS If you're referring to the terminating decimals, the decimals are only terminating if they divide a power of 10. Ex: 2980232238769531250 has a terminating decimal expansion, as it divides a power of 10, as its prime factorization only consist of 2 and 5.

[759009946576]

@HAMLETOIS The length of the repeating number that is the decimal expansion of 1/p. Jwm is describing a long prime, a prime in which 1/p has a repeating number of length p-1. Ex: 1/17 = 0.(0588235294117647), and the section in parentheses is the repeating number.

[emmanueltt3]

?????????????what???