38 (number)

Template:Refimprove Template:Infobox number 38 (thirty-eight) is the natural number following 37 and preceding 39.

In mathematics

• 38! − 1 yields Template:Val which is the 16th factorial prime.<ref>Template:Cite OEIS</ref>
• There is no answer to the equation φ(x) = 38, making 38 a nontotient.<ref>(sequence A005277 in the OEIS)</ref>
• 37 and 38 are the first pair of consecutive positive integers not divisible by any of their digits.
• 38 is the largest even number which cannot be written as the sum of two odd composite numbers.
• The sum of each row of the only non-trivial (order 3) magic hexagon is 38.<ref>Template:Cite book</ref>

In science

• The atomic number of strontium

Astronomy

• The Messier object M38, a magnitude 7.0 open cluster in the constellation Auriga
• The New General Catalogue object NGC 38, a spiral galaxy in the constellation Pisces

In other fields

File:ColorBlindTest38.png

Ishihara test: Most people will see the number 38, but people with red-green color blindness might see 88 instead.

Thirty-eight is also:

• The 38th parallel north is the pre-Korean War boundary between North Korea and South Korea.<ref>{{#invoke:citation/CS1|citation

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• The number of slots on an American roulette wheel (0, 00, and 1 through 36; European roulette does not use the 00 slot and has only 37 slots)
• The Ishihara test is a color vision test consisting of 38 pseudoisochromatic plates.<ref>{{#invoke:citation/CS1|citation

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• A "38" is often the name for a snub nose .38 caliber revolver.
• The 38 class is the most famous class of steam locomotive used in New South Wales
• Gerald Ford, 38th President of the United States
• Arnold Schwarzenegger, 38th Governor of California, most recent Republican governor of California, and the second governor to be born outside of the United States
• Cats have a total of 38 chromosomes in their genome.
• Number used by Zane Smith and Front Row Motorsports to win the 2022 NASCAR Camping World Truck Series championship.

See also

• List of highways numbered 38