To call natural number n "good number" should satisfy the following conditions in decimal system: 1. N is a four digit number; 2. The first and third digits of N are the same; 3. The second and fourth digits of N are the same; 4. The product of the numbers of n is a divisor of the quadratic power of n Try to find all good numbers

To call natural number n "good number" should satisfy the following conditions in decimal system: 1. N is a four digit number; 2. The first and third digits of N are the same; 3. The second and fourth digits of N are the same; 4. The product of the numbers of n is a divisor of the quadratic power of n Try to find all good numbers

one thousand one hundred and eleven
one thousand two hundred and twelve
one thousand five hundred and fifteen
two thousand four hundred and twenty-four
three thousand six hundred and thirty-six

Three continuous natural numbers, the smallest one can be divided by 15, the middle one can be divided by 17, and the largest one can be divided by 21
the sooner the better,

There should be no such three numbers

Try to find 21 consecutive natural numbers, so that each of them can be divided by a natural number from 2 to 13

The conclusion can be stronger: make every number divisible by a natural number from 2 to 11
If we first construct the factorial of 11, that is, 11, then
11! - 10, 11! - 9, 11! - 8, 11! - 7,. 11!, 11! + 1,... 11! + 10 are qualified