The crisp new dollar bill that I have just taken from my wallet bears the serial number 24598176. It’s easy to tell that the number is exactly divisible by 2 but not by 5. Is it divisible by 3? by 4?

Prime numbers, vital in mathematics and competitive exams, can be quickly identified using a systematic approach. This method involves checking divisibility by primes up to the square root of the ...

Prime numbers are the ones that have only two factors: 1 and itself. Credit: Ssindhwani / Wikimedia Commons Prime numbers are those divisible only by themselves and by one. Despite their apparent ...