It is easiest to explain with an example. Suppose you have a number 4627. Then the number obtained by reversing [the order of] its digits is 7264. The difference between them is the bigger number minus the smaller number. So here it would be 7264 - 4627 = 2637.
A reversible prime is a number such as 37, where reversing the order of the digits gives 73 which is also a prime.
No, reversing the order of the digits of a two-digit prime number does not always result in a prime number.
10 digits are numbers in the billions.
There are 5 numbers of 1 digit, 25 numbers of 2 digits, and 75 numbers of 3 digits. This makes 105 numbers in all.
The units digit of a two digit number exceeds twice the tens digit by 1. Find the number if the sum of its digits is 10.
there are 899 whole numbers that have three digits.
any of the following numbers works ...12, 23, 34, 45, 56, 67, 78, 89,
The number is 36.
Armstrong numbers are the sum of their own digits to the power of the number of digits.