38 (number)

← 37 38 39 →
← 30 31 32 33 34 35 36 37 38 39 → List of numbers ; Integers ; ← 0 10 20 30 40 50 60 70 80 90 →
Cardinal	thirty-eight
Ordinal	38th; (thirty-eighth)
Factorization	2 × 19
Divisors	1, 2, 19, 38
Greek numeral	ΛΗ´
Roman numeral	XXXVIII
Binary	1001102
Ternary	11023
Senary	1026
Octal	468
Duodecimal	3212
Hexadecimal	2616

Last updated May 12, 2024

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

In mathematics

specifically, the 11th discrete Semiprime,^[1] it being the 7th of the form (2.q).
the first member of the third cluster of two discrete semiprimes 38, 39 the next such cluster is 57, 58.
with an aliquot sum of 22 in an aliquot sequence of five composite numbers (38,22,14,10,8,7,1,0) to the Prime in the 7-aliquot tree. 34 is the first semiprime within a chain of 4 semiprimes in its aliquot sequence (38,22,14,10). The next semiprime with a four semiprime chain is 166.
38! − 1 yields 523022617466601111760007224100074291199999999 which is the 16th factorial prime.^[2]
There is no answer to the equation φ(x) = 38, making 38 a nontotient.^[3]
38 is the sum of the squares of the first three primes.
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.^[4]

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

Ishihara test: Most people will see the number 38, but people with red-green color blindness might see 88 instead. 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.^[5]
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.^[6]
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.
The Lucky 38, the casino from Fallout: New Vegas.

Related Research Articles

15 (fifteen) is the natural number following 14 and preceding 16.

21 (twenty-one) is the natural number following 20 and preceding 22.

33 (thirty-three) is the natural number following 32 and preceding 34.

27 is the natural number following 26 and preceding 28.

69 is the natural number following 68 and preceding 70. An odd number and a composite number, 69 is divisible by 1, 3, 23 and 69. 69 is a semiprime because it is a natural number that is the product of exactly two prime numbers, and an interprime between the numbers of 67 and 71. Because 69 is not divisible by any square number other than 1, it is categorised as a square-free integer. 69 is also a Blum integer since the two factors of 69 are both Gaussian primes. In number theory, 69 is a deficient number, arithmetic number and a congruent number.

35 (thirty-five) is the natural number following 34 and preceding 36.

82 (eighty-two) is the natural number following 81 and preceding 83.

85 (eighty-five) is the natural number following 84 and preceding 86.

86 (eighty-six) is the natural number following 85 and preceding 87.

87 (eighty-seven) is the natural number following 86 and preceding 88.

74 (seventy-four) is the natural number following 73 and preceding 75.

34 (thirty-four) is the natural number following 33 and preceding 35.

39 (thirty-nine) is the natural number following 38 and preceding 40.

46 (forty-six) is the natural number following 45 and preceding 47.

55 (fifty-five) is the natural number following 54 and preceding 56.

57 (fifty-seven) is the natural number following 56 and preceding 58.

58 (fifty-eight) is the natural number following 57 and preceding 59.

62 (sixty-two) is the natural number following 61 and preceding 63.

65 (sixty-five) is the natural number following 64 and preceding 66.

91 (ninety-one) is the natural number following 90 and preceding 92.

References

↑ Sloane, N. J. A. (ed.). "SequenceA001358". The On-Line Encyclopedia of Integer Sequences . OEIS Foundation.
↑ Sloane, N. J. A. (ed.). "SequenceA002982(Numbers n such that n! - 1 is prime)". The On-Line Encyclopedia of Integer Sequences . OEIS Foundation. Retrieved 2016-05-31.
↑ (sequence A005277 in the OEIS )
↑ Higgins, Peter (2008). Number Story: From Counting to Cryptography . New York: Copernicus. p. 53. ISBN 978-1-84800-000-1.
↑ Fry, Michael (5 August 2013). "National Geographic, Korea, and the 38th Parallel". National Geographic. Archived from the original on February 25, 2021. Retrieved 15 May 2021.
↑ Fluck, Daniel (23 March 2010). "Color Blindness Tests". Colblinder. Retrieved 30 November 2022.

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[1] Sloane, N. J. A. (ed.). "SequenceA001358". The On-Line Encyclopedia of Integer Sequences . OEIS Foundation.

[2] Sloane, N. J. A. (ed.). "SequenceA002982(Numbers n such that n! - 1 is prime)". The On-Line Encyclopedia of Integer Sequences . OEIS Foundation. Retrieved 2016-05-31.

[3] (sequence A005277 in the OEIS )

[4] Higgins, Peter (2008). Number Story: From Counting to Cryptography . New York: Copernicus. p. 53. ISBN 978-1-84800-000-1.

[5] Fry, Michael (5 August 2013). "National Geographic, Korea, and the 38th Parallel". National Geographic. Archived from the original on February 25, 2021. Retrieved 15 May 2021.

[6] Fluck, Daniel (23 March 2010). "Color Blindness Tests". Colblinder. Retrieved 30 November 2022.

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