105
domain: N
Properties
Digital Properties
- Digit Count
- 3
- Digit Sum
- 6
- Digital Root
- 6
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 192
- Proper Divisor Sum (Aliquot Sum)
- 87
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Highly Composite
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 48
- Möbius Function
- -1
- Radical
- 105
- 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
- yes
- 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
- 38
- 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
- no
- Odd
- yes
Names
- German
- einshundertfünf· ordinal: einshundertfünfste
- English
- one hundred five· ordinal: one hundred fifth
- Spanish
- ciento cinco· ordinal: 105º
- French
- cent cinq· ordinal: cent cinqième
- Italian
- centocinque· ordinal: 105º
- Latin
- centum quinque· ordinal: 105.
- Portuguese
- cento e cinco· ordinal: 105º
Appears in sequences
- Let k = p_1^e_1 p_2^e_2 p_3^e_3 ... be the prime factorization of n. Sequence gives k such that the sum of the numbers of 1's in the binary expansions of e_1, e_2, e_3, ... is odd.at n=50A000028
- Numbers k such that (2k)^4 + 1 is prime.at n=30A000059
- A nonlinear binomial sum.at n=7A000128
- Lower Wythoff sequence (a Beatty sequence): a(n) = floor(n*phi), where phi = (1+sqrt(5))/2 = A001622.at n=64A000201
- a(8i+j) = 13i + a(j), where 1<=j<=8.at n=64A000202
- Tribonacci numbers: a(n) = a(n-1) + a(n-2) + a(n-3) with a(0)=a(1)=a(2)=1.at n=9A000213
- E.g.f.: -log(1+log(1+log(1-x))).at n=3A000268
- 3*n - 2*floor(sqrt(4*n+5)) + 5.at n=42A000277
- Number of 6-dimensional partitions of n.at n=3A000416
- Euler transform of A000389.at n=3A000417
- Numbers that are the sum of 3 but no fewer nonzero squares.at n=43A000419
- n written in base where place values are positive cubes.at n=32A000433
- Exponential generating function: (1+3*x)/(1-2*x)^(7/2).at n=2A000457
- 1 together with products of 2 or more distinct primes.at n=37A000469
- Number of ways of placing n labeled balls into 3 indistinguishable boxes with at least 2 balls in each box.at n=1A000478
- Number of esters with n carbon atoms up to structural isomerism.at n=6A000632
- Erroneous version of A007535.at n=40A000783
- Total number of 1's in binary expansions of 0, ..., n.at n=41A000788
- Landau's function g(n): largest order of permutation of n elements. Equivalently, largest LCM of partitions of n.at n=15A000793
- Numbers beginning with a vowel in English.at n=19A000852