Answer:
The GCF is 212121
Explanation:
The factors of 424242 are: 1, 2, 3, 6, 7, 9, 13, 14, 18, 21, 26, 37, 39, 42, 49, 63, 74, 78, 91, 98, 111, 117, 126, 147, 182, 222, 234, 259, 273, 294, 333, 441, 481, 518, 546, 637, 666, 777, 819, 882, 962, 1274, 1443, 1554, 1638, 1813, 1911, 2331, 2886, 3367, 3626, 3822, 4329, 4662, 5439, 5733, 6734, 8658, 10101, 10878, 11466, 16317, 20202, 23569, 30303, 32634, 47138, 60606, 70707, 141414, 212121, 424242
The factors of 636363 are: 1, 3, 7, 9, 13, 21, 27, 37, 39, 49, 63, 91, 111, 117, 147, 189, 259, 273, 333, 351, 441, 481, 637, 777, 819, 999, 1323, 1443, 1813, 1911, 2331, 2457, 3367, 4329, 5439, 5733, 6993, 10101, 12987, 16317, 17199, 23569, 30303, 48951, 70707, 90909, 212121, 636363
HOPE THIS HELPS :)