12806
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 17
- Digital Root
- 8
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 20280
- Proper Divisor Sum (Aliquot Sum)
- 7474
- 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
- -1
- Radical
- 12806
- 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
- 169
- Smith Number
- no
- Vampire 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
Appears in sequences
- McKay-Thompson series of class 42A for Monster.at n=51A058671
- Number of planar n X n X n binary triangular grids symmetric both under 120 degree rotation and reflection with no more than 4 ones in any 3 X 3 X 3 subtriangle.at n=12A153931
- Number of n X n symmetric 0..7 arrays with no element equal to any horizontal or vertical neighbor and with new values 0..7 introduced in lower triangular row major order.at n=3A193273
- Number of n X 4 0..1 arrays with rows and columns lexicographically nondecreasing read forwards, and nonincreasing read backwards.at n=18A201371
- Number of non-equivalent ways to choose three points in an equilateral triangle grid of side n.at n=11A230723
- G.f. satisfies: A(x) = (1+x+x^2) * A(x^2)^2.at n=35A237651
- Number of partitions of n into prime power parts (not including 1) that do not divide n.at n=65A300580
- Square array, read by rows. For n,d >= 0, a(n,d) is the number of congruences of the d-twisted partition monoid of degree n.at n=40A340914
- a(n) = 13*n^2 + 10*n + 3.at n=31A387659