Definitions

1. noun

A Carmichael number is a composite number n such that for every base b, the number n-1 is not divisible by the number b-1 if b^n-1 is divisible by n. This number is also known as a relatively prime to all the bases.

“The mathematician discovered that 561 is a Carmichael number, meeting the conditions of the theorem.”

2. proper noun

A surname of Scottish origin, possibly derived from the Gaelic words ‘cairn’ meaning ‘crag’ and ‘michal’ meaning ‘lord of the castle’.

“Carmichael is a common surname found in Scotland and Ireland.”

3. proper noun

A Carmichael is also the name of a lunar impact crater located on the Moon’s surface.

“The Carmichael crater is a notable impact crater on the Moon’s surface.”

4. proper noun

Carmichael is also the name of a suburb in Canberra, Australia.

“Carmichael is a residential area in Canberra with various parks and amenities.”