12728
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 20
- Digital Root
- 2
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 16
- Divisor Sum
- 25080
- Proper Divisor Sum (Aliquot Sum)
- 12352
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 6048
- Möbius Function
- 0
- Radical
- 3182
- Omega Function (Ω)
- 5
- 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
- 107
- 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
- Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 11 ones.at n=28A031779
- Rounded volume of a regular octahedron with edge length n.at n=30A071400
- Number of diagonal rectangles with corners on an n X n grid of points.at n=15A113751
- a(n) = (A114043(n) - 1)/2.at n=16A115005
- Those positive integers n where, when written in binary, there are exactly k number of runs (of either 0's or 1's) each of exactly k length, for all k where 1<=k<=m, for some positive integer m.at n=19A175356
- G.f. satisfies: A(x) = Product_{n>=1} (1 + x^(n+1)*A(x)) / (1 - x^n).at n=12A209357
- a(n) = n*(19*n-15)/2.at n=37A226490
- Number of partitions of n such that (greatest part) + (least part) > number of parts.at n=36A237871
- Expansion of (phi(q) / phi(q^3))^2 in powers of q where phi() is a Ramanujan theta function.at n=37A261321
- Sum of squares of parts of the partitions of 2n into two squarefree parts.at n=24A280316
- Total sum of parts which are cubes in all partitions of n.at n=26A342229
- Three-column array giving list of primitive triples for integer-sided triangles with A < B < C < 2*Pi/3 and such that FA, FB, FC are also integers where F is the Fermat point of the triangle.at n=24A352360
- a(n) = Sum_{j=1..n} Sum_{k=1..n} phi(j*k) / phi(k).at n=31A372636
- Smallest positive number divisible by n that has n letters in US English, or 0 if none exists.at n=34A384131
- Consecutive states of the linear congruential pseudo-random number generator for Smalltalk-80 when started at 1.at n=15A384220
- a(n) = Sum_{k=0..floor(2*n/9)} binomial(2*n-7*k,2*k).at n=18A392399