12219
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 15
- Digital Root
- 6
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 16296
- Proper Divisor Sum (Aliquot Sum)
- 4077
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 8144
- Möbius Function
- 1
- Radical
- 12219
- 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
- 37
- Smith Number
- no
- 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
- Numbers k such that the continued fraction for sqrt(k) has period 82.at n=39A020421
- Numbers whose base-4 representation contains exactly three 2's and four 3's.at n=10A045152
- If p(x) is the x-th prime, then the n-th set of 4 consecutive sexy prime pairs starts at p(a(n)).at n=19A095963
- Where records occur in A119451.at n=16A119453
- a(n) = (2*n)^n+(2*n+1)^n-(2*n+2)^n.at n=5A127696
- Nonascending wiggly sums: number of sums adding to n in which terms alternately do not increase and do not decrease.at n=18A129853
- a(n) = the least integer > n such that r(1)|a(n), r(2)|(a(n)+1), r(3)|(a(n)+2),... and r(n)|(a(n)+n-1), where (r(1),r(2),r(3),...,r(n)) is some permutation of (1,2,3,...,n).at n=17A138588
- Floor of entry (2,1) of [0,1; 1,phi]^n.at n=13A139333
- A transform of A103210.at n=5A166696
- A leading coefficient adjusted symmetrical triangle of polynomial coefficients based on:p(x,n)=Sum[k!*Binomial[x, k], {k, 0, n}].at n=40A176664
- Number of partitions p = [x(1), ..., x(k)], where x(1) >= x(2) >= ... >= x(k), of n such that max(x(i) - x(i-1)) >= number of distinct parts of p.at n=37A241821
- G.f. satisfies: A(x) = exp( Sum_{n>=1} A(x)^n * (x^n/n) / (1 + x^n) ).at n=11A262784
- Magic sums of 3 X 3 semimagic squares composed of squares.at n=20A265198
- Magic sums of 3 X 3 semimagic squares composed of positive squares.at n=18A269061
- Magic sums of 3 X 3 semimagic squares composed of odd squares.at n=2A269297
- Number of generalized Young tableaux with constant rows, weakly increasing columns, and entries summing to n.at n=21A323582
- Number T(n,k) of partitions of [n] having exactly k parity changes within their blocks, n>=0, 0<=k<=max(0,n-1), read by rows.at n=47A363493
- Number of partitions of [n] having exactly one parity change within their blocks.at n=10A363511
- Lesser of 2 successive squarefree semiprimes (k, k+4) sandwiching 3 consecutive nonsquarefree numbers.at n=35A363821
- Start with two vertices and draw a circle around each whose radius is the distance between the vertices. The sequence gives the number of regions constructed after n iterations of drawing circles with this same radius around every new vertex created from all circles' intersections.at n=49A374337