12006
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 9
- Digital Root
- 9
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 24
- Divisor Sum
- 28080
- Proper Divisor Sum (Aliquot Sum)
- 16074
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 3696
- Möbius Function
- 0
- Radical
- 4002
- Omega Function (Ω)
- 5
- Little Omega Function (ω)
- 4
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
- yes
- Narcissistic Number
- no
- Collatz Steps
- 42
- 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
- Vampire numbers: (definition 1): n has a nontrivial factorization using n's digits.at n=25A020342
- 21-gonal numbers: a(n) = n*(19n - 17)/2.at n=36A051873
- Smallest composite which when sum of prime factors is repeatedly subtracted reaches a prime after n iterations.at n=24A053093
- Numbers k such that k^6 == 1 (mod 7^4).at n=30A056092
- Numbers n such that zero is never reached by iterating the mapping k -> abs(reverse(lpd(k))-reverse(gpf(k))). lpd(k) is the largest proper divisor and gpf(k) is the largest prime factor of k.at n=31A076425
- Numbers k such that iterating phi(sigma(k)-phi(k)) starting from k leads to the fixed point 8064.at n=16A077096
- Sum of n-th antidiagonal of array in A081998.at n=17A082001
- Numbers n such that P(11*n) is prime where P(n) is the partition number.at n=20A113499
- Egyptian fraction representation for the cube root of 10.at n=2A132486
- a(n) = 10*n^2 - 7*n + 1.at n=35A158186
- a(n) = 5*7^n+1.at n=4A199422
- a(n) = 5*n^2 + 1.at n=49A212656
- Triangle read by rows: absolute values of odd-numbered rows of A225434.at n=6A225415
- Apply the triangle-to-triangle transformation described in the Comments in A159041 to the triangle in A142459.at n=12A225434
- Sum of numbers in the n-th antidiagonal of the reciprocity array of 0.at n=36A259574
- Numbers equidistant from twin prime pairs that are also equidistant from numbers equidistant from twin prime pairs.at n=18A260517
- Numbers n such that the decimal equivalent of the binary reflected Gray code representation of n is a palindromic prime.at n=30A281382
- Number of permutations of [n] avoiding {1234, 1324, 3412}.at n=10A294796
- Triangle T(n,k) read by rows: T(n,k) = number of ways of seating n people around a table for the second time so that k pairs are maintained. Rotated sequences are counted as one.at n=47A326404
- Number of integer partitions of n whose negated first differences (assuming the last part is zero) are not unimodal.at n=34A332744