1903
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 13
- Digital Root
- 4
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 2088
- Proper Divisor Sum (Aliquot Sum)
- 185
- 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
- 1720
- Möbius Function
- 1
- Radical
- 1903
- Omega Function (Ω)
- 2
- Little Omega Function (ω)
- 2
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
- yes
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 130
- Smith Number
- yes
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- yes
- 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
Appears in sequences
- A generalized partition function.at n=15A002598
- a(n) = smallest number with shortest addition chain of length n.at n=15A003064
- Symmetries in planted 4-trees on n+1 vertices.at n=9A003615
- Expansion of (1-x+x^2)/((1-x)^2*(1-x^2)*(1-x^4)).at n=42A005232
- Number of partitions of n into parts of sizes {a( )} is a(n).at n=38A007209
- Coordination sequence T4 for Zeolite Code DOH.at n=27A008081
- Coordination sequence T2 for Coesite.at n=23A008268
- Coordination sequence T4 for Zeolite Code VNI.at n=27A009910
- Generalized Catalan Numbers x^3*A(x)^2 + (x-1)*A(x) + 1 =0.at n=13A023431
- Numbers with exactly 9 ones in binary expansion.at n=29A023691
- a(n) = s(1)*t(n) + s(2)*t(n-1) + ... + s(k)*t(n-k+1), where k = [ n/2 ], s = (F(2), F(3), F(4), ...), t = (odd natural numbers).at n=15A025106
- a(n) = a(1)*a(n-1) + a(2)*a(n-2) + ... + a(n-3)*a(3) for n >= 4, with initial terms 1, 0, 1, 1.at n=15A025246
- a(n) = (d(n) - r(n))/5, where d = A026037 and r is the periodic sequence with fundamental period (1,2,0,2,0).at n=28A026039
- a(n) is the sum of the non-Fibonacci numbers in row n of array T given by A027935, computed as T(n,m) + T(n,m+1) + ... + T(n,n-1), where m = floor((n+2)/2).at n=11A027946
- a(n) = n^6 - (883/60)*n^5 + (157/3)*n^4 + (2155/12)*n^3 - (4570/3)*n^2 + (42767/15)*n - 967.at n=1A028295
- Numbers k such that 179*2^k+1 is prime.at n=16A032466
- Position of first occurrence of n in the continued fraction for the Euler-Mascheroni constant (gamma).at n=44A033149
- Number of partitions of n into parts 4k or 4k+1.at n=47A035362
- Upper of pair of consecutive happy numbers.at n=42A035503
- Numbers n such that digit sum of n equals digit sum of 'juxtaposition' and 'sum' of its prime factors (counted with multiplicity).at n=35A036921