Square root of 553 is less, than 24, so we should only check the division by the numbers less than 24. 553 is not divided by 2, 3, 5, ... But, it is divided by 7, so, it is composite/
276.5
79
0.0018
7 x 79 = 553
3.6867
Square root of 553 is less, than 24, so we should only check the division by the numbers less than 24. 553 is not divided by 2, 3, 5, ... But, it is divided by 7, so, it is composite/
7.473
276.5
79
55-3 = 52
0.0018
553/23= 24.0434782...... So, no.
55 plus 553 is 608
7 x 79 = 553
The ISBN of Brightness Reef is 0-553-10034-3.
The ISBN of Stopping at Slowyear is 0-553-29487-3.