Professor Cardy

Prime Number Calculator

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Enter an integer (max. 1,000,000)


90599 is a prime number.

About the Calculator

This calculator performs the decomposition of a number into its prime factors and lists all its natural divisors. Enter an integer between 1 and 1,000,000.

Curiosities

1) Relation to multiples of 6: Every prime number greater than 3 is always one less or one more than a multiple of 6.
Example: `90599` is 1 less than `90600` (multiple of 6).

2) Square minus 1 divisible by 24: For every prime number greater than 3, if 1 is subtracted from its square, the result is always divisible by 24.
Example: The square of `90599` is `8208178801`. Subtracting 1, we get `8208178800`. Note that `8208178800 ÷ 24 = 342007450`.

3) Difference of squares: Every prime number greater than 2 can be expressed as the difference of the squares of two consecutive natural numbers.
Example: `90599 = 45300^2 - 45299^2 = 2052090000 - 2051999401`

4) Form `4n+1` or `4n-1`: Except for the number 2, all prime numbers follow the pattern `4n+1` or `4n-1`, where `n` is a natural number.
Example: `90599` is of the form `4n-1`, where `n = 22650`.

The First 10,000 Prime Numbers