1216
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 10
- Digital Root
- 1
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 14
- Divisor Sum
- 2540
- Proper Divisor Sum (Aliquot Sum)
- 1324
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Highly Composite
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 576
- Möbius Function
- 0
- Radical
- 38
- Omega Function (Ω)
- 7
- 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
- no
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 26
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- no
- Squarefree Number
- no
- 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
Appears in sequences
- 9-gonal (or enneagonal or nonagonal) numbers: a(n) = n*(7*n-5)/2.at n=19A001106
- Number of cells of square lattice of edge 1/n inside quadrant of unit circle centered at 0.at n=39A001182
- Expansion of 1/(1-x)^2/(1-x^2)/(1-x^4)/(1-x^10)/(1-x^20).at n=30A001307
- Expansion of e.g.f. exp(-x - (1/2)*x^2).at n=10A001464
- Related to Zarankiewicz's problem.at n=47A001841
- Numbers that are the sum of 2 positive cubes.at n=48A003325
- Numbers that are the sum of 6 positive 5th powers.at n=31A003351
- Numbers that are the sum of 7 positive 5th powers.at n=36A003352
- Internal energy series for b.c.c. lattice.at n=3A003497
- Number of spanning trees with degrees 1 and 3 in W_4 X P_n.at n=3A003768
- a(n) = floor(n*phi^9), where phi is the golden ratio, A001622.at n=16A004924
- a(n) = round(n*phi^9), where phi is the golden ratio, A001622.at n=16A004944
- Numbers k such that sigma(x) = k has exactly 3 solutions.at n=31A007372
- a(n) = phi(n) * (sigma(n) - n).at n=47A007517
- Coordination sequence T3 for Zeolite Code AFO.at n=23A008017
- Coordination sequence T3 for Zeolite Code MTN.at n=21A008188
- Coordination sequence T5 for Zeolite Code NON.at n=21A008216
- Expansion of e.g.f.: cosh(tan(log(1+x))).at n=6A009156
- Coordination sequence for sigma-CrFe, Position Xf.at n=9A009958
- Partial sums of A003136.at n=31A014146