prime!

small selection of nice primes
up to 16 digits (as decimal numbers)

1333333333333333
277
2777
2777777777
2777777777777777
511111
5111111111111
5111111111111111
877
8777777777
8777777777777777

7999999999999999 = 199999 x 40000200001

13
113
11113
111111113
11111111113

31
331
3331
33331
333331
3333331
33333331

555555555551
5555555555551

7777777777771

22222222222227 = 3 x 7407407407409
222222222222227

555555555555557

91919191919

737373737373737

6000000000000001

9000000000000007

23----89
--4567--
23456789
234567899
234567899999999
   567899999
   567899

899999999999999 is product of twin primes, 60000000 their sum
 
palindromes with increasing-decreasing numerical sequence are products of prime squares
121 = 1^2 x 11^2
12321 = 3^2 x 37^2
1234321 = 11^2 x 101^2
123454321 = 41^2 x 271^2
12345654321 = 3^2 x 7^2 x 11^2 x 13^2 x 37^2
1234567654321 = 239^2 x 4649^2
123456787654321 = 11^2 x 73^2 x 101^2 x 137^2
...

    strange world
 

    8128
 
    © W. Daeumler, phone +49 emirp(368141)x(prime following 106937)