21756980

素因数分解:

$2^2\times 5^1\times 7^2\times {\mathrm{149}}^2$

素因数の和:321

約数の個数: 54

約数和(自身を含む): 53508294

約数和(自身を除く): 31751314

約数列:

[1, 2, 4, 5, 7, 10, 14, 20, 28, 35, 49, 70, 98, 140, 149, 196, 245, 298, 490, 596, 745, 980, 1043, 1490, 2086, 2980, 4172, 5215, 7301, 10430, 14602, 20860, 22201, 29204, 36505, 44402, 73010, 88804, 111005, 146020, 155407, 222010, 310814, 444020, 621628, 777035, 1087849, 1554070, 2175698, 3108140, 4351396, 5439245, 10878490, 21756980]

約数ペア:

[(1, 21756980), (2, 10878490), (4, 5439245), (5, 4351396), (7, 3108140), (10, 2175698), (14, 1554070), (20, 1087849), (28, 777035), (35, 621628), (49, 444020), (70, 310814), (98, 222010), (140, 155407), (149, 146020), (196, 111005), (245, 88804), (298, 73010), (490, 44402), (596, 36505), (745, 29204), (980, 22201), (1043, 20860), (1490, 14602), (2086, 10430), (2980, 7301), (4172, 5215)]