79
553
9 times, with 13 left over
The rule being used here is probably a recursive one: xn+2 = xn + xn+1 + 2 For instance, 48 = 17 + 29 + 2. Thus the nextnumber is: 29 + 48 + 2 = 79 And the series can be extended indefinitely in both directions, if we like: ...-39, 21, -16, 7, -7, 2, -3, 1, 0, 3, 5, 10, 17, 29, 48, 79, 129, 210, 341, 553...
There are infinitely many multiples of 7, they start: 7, 14, 21, 28, 35, 42, 49, 56, 63, 70, 77, 84, 91, 98, 105, 112, 119, 126, 133, 140, 147, 154, 161, 168, 175, 182, 189, 196, 203, 210, 217, 224, 231, 238, 245, 252, 259, 266, 273, 280, 287, 294, 301, 308, 315, 322, 329, 336, 343, 350, 357, 364, 371, 378, 385, 392, 399, 406, 413, 420, 427, 434, 441, 448, 455, 462, 469, 476, 483, 490, 497, 504, 511, 518, 525, 532, 539, 546, 553, 560, 567, 574, 581, 588, 595, 602, 609, 616, 623, 630, 637, 644, 651, 658, 665, 672, 679, 686, 693, 700, ...
7, 14, 21, 28, 35, 42, 49, 56, 63, 70, 77, 84, 91, 98, 105, 112, 119, 126, 133, 140, 147, 154, 161, 168, 175, 182, 189, 196, 203, 210, 217, 224, 231, 238, 245, 252, 259, 266, 273, 280, 287, 294, 301, 308, 315, 322, 329, 336, 343, 350, 357, 364, 371, 378, 385, 392, 399, 406, 413, 420, 427, 434, 441, 448, 455, 462, 469, 476, 483, 490, 497, 504, 511, 518, 525, 532, 539, 546, 553, 560, 567, 574, 581, 588, 595, 602, 609, 616, 623, 630, 637, 644, 651, 658, 665, 672, 679, 686, 693, 700, 707, 714, 721, 728, 735, 742, 749, 756, 763, 770, 777, 784, 791, 798, 805, 812, 819, 826, 833, 840, 847, 854, 861, 868, 875, 882, 889, 896, 903, 910, 917, 924, 931, 938, 945, 952, 959, 966, 973, 980, 987, 994.
7.473
276.5
3.6867
184.3333
79
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/
0.0018
7 x 79 = 553
55 plus 553 is 608
553/23= 24.0434782...... So, no.
The number 553 in roman numerals is: DLIII
553 feet = 16,855.44 centimeters