odd number

[ od nuhm-ber ]

noun

1. a number that leaves a remainder of 1 when divided by 2:

   7, 13, and 195 are odd numbers.

Word History and Origins

Origin of odd number¹

First recorded in 1350–1400

Example Sentences

Anybody in the federal bureaucracy who is not elected … if your Social Security number ends in an odd number, you’re out.

From Slate

Of those who remain, if your Social Security number starts with an even number, you’re in, and if it starts with an odd number, you’re out.

From Slate

And then there’s the annoying odd number thing, based on the specious notion that readers are more curious about the specificity of, say, nine and 21 than 10 and 20.

From Los Angeles Times

If there’s an odd number of electrons in the wire, the unpaired electron should essentially split in half to form two separated Majorana quasiparticles—one at each end of the wire.

From Science Magazine

More generally, “one can ask about the optimal sizes of Möbius bands that make an odd number of twists,” Tabachnikov says.

From Scientific American