Let's welcome 2021 into our lives with fun facts about the number 2021 itself.
1. Where 2020 was a concatenation of two same natural numbers, 2021 is a concatenation of two successive natural numbers.
2. 2021 can also be written as 20 S(20), where S denotes successor function.
Sucesor Function Wiki - https://en.wikipedia.org/wiki/Successor_function
3. 2021 is one of those numbers which when multiplied by its reversal, produces a palindrome.
4. Sum of divisors of 2021 is palindromic.
5. 2021 is a product of two consecutive primes 43, 47.
6. 43 and 47 are cousin primes because their difference is 4.
Cousin Number Wiki - https://en.wikipedia.org/wiki/Cousin_prime
7. Since 2021 is a product of two primes, it’s called a semiprime.
8. It’s a composite number greater than 9, which yields a prime whenever a ‘0’ is inserted between any two digits.
9. Sum of any two consecutive digits in 2021 is a prime.
10. 2021 is an unusual number since its square root is smaller than the greatest prime factor.
Unusual Number Wiki - https://en.wikipedia.org/wiki/Unusual_number
For More about the integer 2021 click on the link below - https://oeis.org/search?q=2021
#happynewyear #happynewyear2021 #mathematics