• Although composite, 145 is a
Fermat pseudoprime in
sixteen bases with b 145 = 12^2 + 1^2 = 8^2 + 9^2. 145 is the fourth number that is the sum of two different pairs of
squares. Also, 145 is the result of 34 + 43, making it a
Leyland number. • 145 = 1! + 4! + 5!, making it a
factorion. The only other numbers that have this property are
1,
2 and
40585. == References ==