138 (number)

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← 137 138 139 →
Cardinalone hundred thirty-eight
Ordinal138th
(one hundred thirty-eighth)
Factorization2 × 3 × 23
Divisors1, 2, 3, 6, 23, 46, 69, 138
Greek numeralΡΛΗ´
Roman numeralCXXXVIII
Binary100010102
Ternary120103
Quaternary20224
Quinary10235
Senary3506
Octal2128
DuodecimalB612
Hexadecimal8A16
Vigesimal6I20
Base 363U36

138 (one hundred [and] thirty-eight) is the natural number following 137 and preceding 139.

In mathematics[edit]

138 is a sphenic number, the sum of four consecutive primes (29 + 31 + 37 + 41), and the smallest product of three primes, such that in base 10, the third prime is a concatenation of the other two: .

138 is the third 47-gonal number[1] and an Ulam number,[2] as well as a one step palindrome (138 + 831 = 969.)

138 is the 72nd normal congruent number[3] and the 49th primitive or square free congruent number.[4]

In astronomy[edit]

In the military[edit]

In transportation[edit]

In media[edit]

In other fields[edit]

138 is also:

See also[edit]

References[edit]

  1. ^ Sloane, N. J. A. (ed.). "Sequence A095311 (47-gonal numbers)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-05-27.
  2. ^ A002858 in the OEIS
  3. ^ in the OEIS
  4. ^ in the OEIS