6418
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 19
- Digital Root
- 1
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 9630
- Proper Divisor Sum (Aliquot Sum)
- 3212
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Highly Composite
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 3208
- Möbius Function
- 1
- Radical
- 6418
- 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
- no
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 75
- 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
- yes
- Odd
- no
Appears in sequences
- Numbers k such that the continued fraction for sqrt(k) has period 25.at n=23A020364
- a(n) = Sum_{i=0..n} T(i,n-i), array T as in A048149.at n=22A049712
- Numbers n such that 105*2^n-1 is prime.at n=27A050578
- Number of n-digit numbers with nonzero multiplicative digital root 7.at n=5A051818
- Write the numbers from 1 to n^2 in a spiraling square; a(n) is the total of the sums of the two diagonals.at n=17A059924
- a(1)=1, a(n)=2a(n-1)+1 if a(n-1) is prime, a(n)=a(n-1)+1 otherwise.at n=41A083005
- a(n) is the minimal area of a convex lattice polygon with 2n sides.at n=34A089187
- Numbers whose Matula tree is a binary tree (i.e., root has degree 2 and all nodes except root and leaves have degree 3).at n=11A111299
- Matula-Goebel signatures for plane binary trees encoded by A014486.at n=25A127302
- Matula-Goebel signatures for plane binary trees encoded by A014486.at n=34A127302
- G.f. A(x) satisfies A(x) = 1 + x*A(x)^5*A(-x)^2.at n=6A143552
- n^3 - (n+2)^2.at n=19A153258
- Number of -3..3 arrays x(0..n+2) of n+3 elements with zero sum and nonzero second and third differences.at n=2A200199
- T(n,k)=Number of -k..k arrays x(0..n+2) of n+3 elements with zero sum and nonzero second and third differences.at n=12A200204
- Number of -n..n arrays x(0..5) of 6 elements with zero sum and nonzero second and third differences.at n=2A200207
- Number of nX4 0..1 arrays avoiding 0 0 0 and 0 1 1 horizontally and 0 0 0 and 1 0 1 vertically.at n=5A207781
- T(n,k)=Number of nXk 0..1 arrays avoiding 0 0 0 and 0 1 1 horizontally and 0 0 0 and 1 0 1 vertically.at n=41A207785
- Number of 6Xn 0..1 arrays avoiding 0 0 0 and 0 1 1 horizontally and 0 0 0 and 1 0 1 vertically.at n=3A207788
- The 240-degree spoke (or ray) of a hexagonal spiral of Ulam.at n=23A244805
- Triangle read by rows: row n>=1 contains in increasing order the Matula numbers of the rooted binary trees with n leaves.at n=12A245824