Is 1 a Prime Number???

We have been exposed about odd numbers, even numbers, composite numbers, prime numbers and a lot lot lot of numbers in mathematics since primary school.

Out of all those numbers mentioned above, I am very excited to share a delicious discovery about Prime Number (The Atoms of Mathematics).


  • a whole number which cannot be divided by any other whole number except 1 and itself


  • 2  3  5  7  11  13  17  19  23  29  31  37  41  43  47  53  59  61  67  71  73  79  83  89  97

Have you eat THE FIRST 25 PRIMES? Did you tasted the sourness in it? I did! The sour taste trigger me to argue WHY 1 IS NOT A PRIME NUMBER?

From the definition, it is clearly seen that 1 can be divided by 1 and of course ITSELF! But why it is excluded from the primes? Lets kick the sour out 😋

First of all, we should recall the Fundamental Theorem of Arithmetic.


  • every positive whole number can be written as a UNIQUE product of primes

Lets take a bite on this simple snacks;

Take 10 (ten) as an example. Assume 1 is a prime number. By using the Fundamental Theorem of Arithmetic, we have:

10 = 2 x 5 or 5 x 2 (we don’t really mind the order)

10 = 1 x 2 x 5

10 = 1 x 1 x 2 x 5

10 = 1 x 1 x 1 x 2 x 5 (and so on)

From here, we can see if 1 is a prime  then we wouldn’t have a UNIQUE way of writing 10 as the product of prime numbers. So, that is why 1 is EXCLUDED from the list of prime number.

Yummmyy! We solved the mystery of Prime Number deliciously. 🍦

Till the next lunch date everyone!!!



One thought on “Is 1 a Prime Number???

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