Definition:Giuga Number/Mistake

Source Work

1997: David Wells: Curious and Interesting Numbers (2nd ed.):

The Dictionary

$30$

Mistake

$1/2 + 1/3 + 1/5 - 1/30 = 1$, so $30$ is a Guiga number, the smallest.

The name is Giuseppe Giuga, not Guiga.

The mistake is repeated in entry $244,197,000,982,499,715,087,866,346$:

A large Guiga number, equal to $2 \times 3 \times 11 \times 23 \times 31 \times 47 \, 137 \times 28 \, 282 \, 147 \times 3 \, 892 \, 535 \, 183$.

Sources

• 1997: David Wells: Curious and Interesting Numbers (2nd ed.) ... (previous) ... (next): $30$