38 (number)

In mathematics

• 38! − 1 yields which is the 16th factorial prime.
• There is no answer to the equation φ = 38, making 38 a nontotient.
• 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 magic hexagon is 38.

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

• The 38th parallel north is the pre-Korean War boundary between North Korea and South Korea.
• The number of slots on an American roulette wheel
• The Ishihara test is a color vision test consisting of 38 pseudoisochromatic plates.
• 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.