138
domain: N
Properties
Digital Properties
- Digit Count
- 3
- Digit Sum
- 12
- Digital Root
- 3
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 288
- Proper Divisor Sum (Aliquot Sum)
- 150
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Highly Composite
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- yes
Derived Values
- Euler's Totient
- 44
- Möbius Function
- -1
- Radical
- 138
- Omega Function (Ω)
- 3
- Little Omega Function (ω)
- 3
Special
- Factorial
- no
- Catalan Number
- no
- Bell Number
- no
- Motzkin Number
- no
- Primorial
- no
Figurate Numbers
- Fibonacci Number
- no
- Triangular Number
- no
- Perfect Square
- no
- Perfect Cube
- no
- Pentagonal Number
- no
- Hexagonal Number
- no
- Lucas Number
- no
- Tetrahedral Number
- no
- Pell Number
- no
- Tribonacci Number
- no
- Pronic Number
- no
Recreational
- Happy Number
- no
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 15
- Smith Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- no
- Squarefree Number
- yes
- Prime Power
- no
- Prime Factorization
- no
- Twin Prime
- no
- Mersenne Prime
- no
- Sophie Germain Prime
- no
- Safe Prime
- no
- Powerful Number
- no
- Achilles Number
- no
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- yes
- Odd
- no
Names
- German
- einshundertachtunddreißig· ordinal: einshundertachtunddreißigste
- English
- one hundred thirty-eight· ordinal: one hundred thirty-eighth
- Spanish
- ciento treinta y ocho· ordinal: 138º
- French
- cent trente-huit· ordinal: cent trente-huitième
- Italian
- centotrentotto· ordinal: 138º
- Latin
- centum triginta octo· ordinal: 138.
- Portuguese
- cento e trinta e oito· ordinal: 138º
Appears in sequences
- Numbers k such that (2k)^4 + 1 is prime.at n=39A000059
- Number of unrooted nonseparable planar maps with n edges and a distinguished face.at n=6A000087
- Number of partitions into non-integral powers.at n=8A000148
- Numbers that are the sum of 3 but no fewer nonzero squares.at n=58A000419
- 1 together with products of 2 or more distinct primes.at n=51A000469
- Number of loops of length 4n on square grid that turn at each step and return to start in original direction.at n=5A000644
- Boustrophedon transform of 1, 2, 2, 2, 2, ...at n=5A000674
- Number of centered 3-valent (or boron, or binary) trees with n nodes.at n=13A000675
- Expansion of Product_{k >= 1} (1 - x^k)^6.at n=67A000729
- Numbers that are divisible by at least three different primes.at n=16A000977
- Numbers that are the sum of 2 successive primes.at n=18A001043
- Continued fraction for e^2.at n=55A001204
- Number of ways of making change for n cents using coins of 1, 2, 5, 10, 25 cents.at n=34A001301
- Number of ways of making change for n cents using coins of 1, 2, 5, 10, 25, 50 cents.at n=34A001302
- Number of n-step self-avoiding walks on hexagonal [ =triangular ] lattice.at n=3A001334
- Number of connected graphs with n nodes and ceiling(n(n-1)/4) edges.at n=5A001437
- Winning moves in Fibonacci nim.at n=26A001581
- Numbers with an odd number of digits.at n=48A001633
- Upper Wythoff sequence (a Beatty sequence): a(n) = floor(n*phi^2), where phi = (1+sqrt(5))/2.at n=52A001950
- a(n) = floor((n+1/2)*(2+sqrt(2))); winning positions in the 2-Wythoff game.at n=40A001954