I divisori di 990231 sono 16, elencati qui di seguito: 1; 3; 11; 33; 37; 111; 407; 811; 1221; 2433; 8921; 26763; 30007; 90021; 330077; 990231
990212, 990213, 990214, 990215, 990216, 990217, 990218, 990219, 990220, 990221, 990222, 990223, 990224, 990225, 990226, 990227, 990228, 990229, 990230, 990232, 990233, 990234, 990235, 990236, 990237, 990238, 990239, 990240, 990241, 990242, 990243, 990244, 990245, 990246, 990247, 990248, 990249, 990250