Все делители числа 1, 3, 7, 9, 11, 13, 21, 33, 37, 39, 63, 77, 91, 99, 101, 111, 117, 143, 231, 259, 273, 303, 333, 407, 429, 481, 693, 707, 777, 819, 909, 1001, 1111, 1221, 1287, 1313, 1443, 2121, 2331, 2849, 3003, 3333, 3367, 3663, 3737, 3939, 4329, 5291, 6363, 7777, 8547, 9009, 9191, 9901, 9999, 10101, 11211, 11817, 14443, 15873, 23331, 25641, 26159, 27573, 29703, 30303, 33633, 37037, 41107, 43329, 47619, 48581, 69307, 69993, 78477, 82719, 89109, 101101, 108911, 111111, 123321, 128713, 129987, 145743, 207921, 235431, 287749, 303303, 326733, 333333, 340067, 366337, 369963, 386139, 437229, 534391, 623763, 762377, 863247, 900991, 909909, 980199, 1000001, 1020201, 1099011, 1158417, 1415843, 1603173, 2287131, 2564359, 2589741, 2702973, 3000003, 3060603, 3297033, 3740737, 4029707, 4247529, 4762381, 4809519, 6861393, 7000007, 7693077, 8108919, 9000009, 9910901, 11000011, 11222211, 12089121, 12742587, 13000013, 14287143, 21000021, 23079231, 28207949, 29732703, 33000033, 33336667, 33666633, 36267363, 37000037, 39000039, 42861429, 52386191, 63000063, 77000077, 84623847, 89198109, 91000091, 99000099, 100010001, 111000111, 117000117, 143000143, 157158573, 231000231, 253871541, 259000259, 273000273, 300030003, 333000333, 366703337, 407000407, 429000429, 471475719, 481000481, 693000693, 777000777, 819000819, 1001001001, 1100110011, 1221001221, 1287001287, 1443001443, 2331002331, 2849002849, 3003003003, 3300330033, 3367003367, 3663003663, 4329004329, 5291005291, 8547008547, 9009009009, 10101010101, 15873015873, 25641025641, 30303030303, 37037037037, 47619047619, 111111111111, 333333333333
Все делители
S = a*b
Отсюда находим ширину - b
b = S : a = 64.8 : 12 = 5.4 см
Периметр прямоугольника по формуле
P = 2*(a + b) = 2*(12 + 5.4) = 2 *17.4 = 34.8 см - периметр - ОТВЕТ