Today is 19 day of the year.

19 is prime.

19 is a happy number.

19 is the fifth member of Flavius Josephus' sieve.

19 is a member of the primitive, Pythagorean triple (19, 80,81)

19 is the smallest prime whose reversal is composite.

19 is strictly non-palindromic as can be seen from its representation in different bases:

2: 10011

3: 201 - In base 3 all digits are used, i.e. 19 is pandigital in base 3.

4: 103

5: 34

6: 31

7: 25

8: 23

9: 21

10: 19

11: 18

12: 17

13: 16

14: 15

15: 14

16: 13

17: 12

19 is the largest prime, p, that is pandigital in some base b > 1 and b < p - 1.

## No comments:

Post a Comment