Weird number

In mathematics, a weird number is a natural number that is abundant but not semiperfect. The first few weird numbers are 70, 836, 4030, 5830, 7192, 7912, 9272, 10430, ... (Sloane's A006037); it has been shown that an infinite number of weird numbers exist, and the sequence of weird numbers has also been proven to have positive Schnirelmann density.

As of today, no odd weird number has been found.

Also see

• Quasiperfect number
• Perfect number
• Deficient number

External links

• MathWorld: Weird number