7091
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 17
- Digital Root
- 8
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 8112
- Proper Divisor Sum (Aliquot Sum)
- 1021
- 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
- 6072
- Möbius Function
- 1
- Radical
- 7091
- 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
- 57
- 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
- a(n) = floor(n*(n - 1)*(n - 2)/32).at n=62A011914
- a(n)=(s(n)+3)/10, where s(n)=n-th base 10 palindrome that starts with 7.at n=31A043086
- Numbers n such that sigma(n) = n-th composite number.at n=10A048886
- Revert transform of (-1 - x + 2*x^2 + x^3)/(-1 - 2*x + 2*x^2 + 2*x^3).at n=15A049148
- Discriminants of real quadratic fields with class number 2 and related continued fraction period length of 24.at n=37A051989
- Engel expansion of log(Pi) = 1.14473... .at n=6A059195
- Interprimes which are of the form s*prime, s=7.at n=7A075282
- G.f.: (1-x+2*x^2+2*x^3+2*x^4-x^5+x^6)/((1-x)*(1-x^2)^2*(1-x^3)).at n=43A083709
- Number of n X n binary arrays symmetric about main diagonal with all ones connected only in a 1100-0110-0011 pattern in any orientation.at n=10A146448
- Number of n X n binary arrays symmetric about the diagonal and under 90 degree rotation with all ones connected only in a 1100-0110-0011 pattern in any orientation.at n=22A146450
- Number of n X n binary arrays symmetric about the diagonal and under 90 degree rotation with all ones connected only in a 1100-0110-0011 pattern in any orientation.at n=23A146450
- 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, 0), (-1, -1, 1), (-1, 1, -1), (0, 1, 1), (1, -1, -1)}.at n=10A148065
- Composite numbers such that exactly ten distinct permutations of digits are prime.at n=12A163562
- Indices of record high-points in the sequence of Sprague-Grundy values for Grundy's game.at n=35A180120
- Number of 4-step S, E, and NW-moving king's tours on an n X n board summed over all starting positions.at n=19A187509
- a(n) = a(n-no-1)+....+a(n-1)+(n-no-2) where no is the 'no+1'th order of the series and 'n' is the element number, here no=6.at n=17A196876
- Number of ways to choose 3 points in an n X n X n triangular grid so that they do not form a 2 X 2 X 2 triangle.at n=6A234250
- a(n) = number of permutations of (1,2,...,n) producible by an ordered quadruple of distinct transpositions.at n=4A253207
- Numbers k such that [r[s*k]] - [s[r*k]] = -2, where r = sqrt(2), s=sqrt(3), and [ ] = floor.at n=32A259584
- Sum of the sizes of the Durfee squares of all no-leg partitions of n (or of all no-arm partitions of n).at n=53A268188