19
This number is a prime.
Just showing those entries submitted by 'Young': (Click here to show all)
Here is the mathematical code to determine if a number is
divisible by 19. Multiply everything in front of the last
digit by nine and subtract the last digit. If you get zero,
nineteen, or a multiple of nineteen, the number will be
divisible by 19. For example 57. Five times nine minus seven
equals 38. Since 19 divides evenly into 38, it divides
evenly into 57. Next example 114. Eleven times nine minus
four equals 95. Since 19 divides evenly into 95, it divides
evenly into 114. [Young]
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