Factorization
80 = 2 × 2 × 2 × 2 × 5
80 has 10 divisors: 1, 2, 4, 5, 8, 10, 16, 20, 40, 80
Sum of all divisors other than 80:
106
Sums & differences
Sum of 2 squares: 80 = 82 + 42
Difference of 2 squares: 80 = 122 - 82 = 212 - 192
Goldbach conjecture: 80 = 73 + 7 = 67 + 13 = 61 + 19 = 43 + 37
