7066
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
- 1
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 10602
- Proper Divisor Sum (Aliquot Sum)
- 3536
- 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
- 3532
- Möbius Function
- 1
- Radical
- 7066
- 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
- 31
- 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
- a(n) is the solution to the postage stamp problem with 6 denominations and n stamps.at n=12A001211
- Numbers k such that the continued fraction for sqrt(k) has period 57.at n=9A020396
- Expansion of g.f.: ((1 - x - sqrt(1-6*x+5*x^2))/(2*x))^2.at n=7A045868
- Catafusenes (see reference for precise definition).at n=6A045902
- Path-counting array T; each step of a path is (1 right) or (1 up) to a point below line y=x, else (1 right and 1 up) or (1 up) to a point on the line y=x, else (1 left) or (1 up) to a point above line y=x. T(i,j)=number of paths to point (i-j,j), for 1<=j<=i, i >= 1.at n=43A055450
- Numbers k for which 10*2^k + 3 is a prime (giving terms of A068712).at n=43A068713
- Triangle of numbers arising in recursive computation of A002212.at n=35A073149
- Numbers k such that k!!!! - 1 is prime.at n=24A085147
- Fibonacci sequence with a(1) = 7 and a(2) = 26.at n=13A098127
- Sum array of Catalan numbers (A000108) read by upward antidiagonals.at n=38A106534
- Number of hierarchical orderings ("societies") of n unlabeled elements ("individuals") with at least two occupied levels.at n=12A110045
- a(n) consecutive digits ascending beginning with the digit 8 give a prime.at n=3A120826
- Binomial transform of [1, 3, 7, 0, 0, 0, ...].at n=45A140063
- Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, -1, -1), (-1, -1, 0), (-1, 1, -1), (0, 1, 1), (1, 0, 0)}.at n=8A149849
- Number of permutations of 1..n containing the relative rank sequence { 42531 } at any spacing.at n=3A158429
- Numbers k such that 6k+1, 12k+1, 18k+1 and 36k+1 are all primes.at n=31A206024
- Number of subsets A of {0,...,n-1} such that A contains 0 and n-1, and |A+A| > |A-A|.at n=25A224893
- Number of zeros of the polynomial Sum_{j=0..n-1} z^(2^j-1) outside the unit circle.at n=13A257593
- Triangle A106534 with reversed rows.at n=42A280470
- Numbers k such that 55*10^k + 7 is prime.at n=15A294376