7143
domain: N
Properties
Digital Properties
- Digit Count
- 4
- 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
- 9528
- Proper Divisor Sum (Aliquot Sum)
- 2385
- 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
- 4760
- Möbius Function
- 1
- Radical
- 7143
- 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
- 194
- 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) = ceiling(n*phi^17), where phi is the golden ratio, A001622.at n=2A004972
- Coordination sequence for alpha-Mn, Position Mn2.at n=22A009951
- a(n) = least m such that if r and s in {F(h)/F(2*h): h = 1,2,...,n} satisfy r < s, then r < k/m < s for some integer k, where F = A000045 (Fibonacci numbers).at n=17A024831
- a(n) = least m such that if r and s in {|F(h+1)-tau*F(h)|: h = 1,2,...,n} satisfy r < s, then r < k/m < s for some integer k, where F = A000045 (Fibonacci numbers) and tau = (1+sqrt(5))/2 (golden ratio).at n=17A024849
- 7-automorphic numbers ending in 3: final digits of 7n^2 agree with n.at n=3A030990
- Numbers k such that the continued fraction for sqrt(k) has even period and if the last term of the periodic part is deleted the central term is 27.at n=39A031525
- Numbers n such that 55*2^n-1 is prime.at n=32A050553
- Let R(i,j) be the rectangle with antidiagonals 1; 2,3; 4,5,6; ...; each k is an R(i(k),j(k)) and A057041(n)=j(F(n)), where F(n) is the n-th Fibonacci number.at n=38A057041
- Beginning with 1, minimum value such that gcd(a(2n-1),a(2n)) = 1, gcd(a(2n),a(2n+1))>1 and a(n) > a(n-1).at n=43A091856
- Numbers n such that (n+j) mod (2+j) = 1 for j from 0 to 5 and (n+6) mod 8 <> 1.at n=8A096024
- a(n) = (7*n^3 + 6*n^2 + 5*n) / 6.at n=18A101165
- Number of partitions of n having nonnegative even rank (the rank of a partition is the largest part minus the number of parts).at n=37A101709
- Triangle, read by rows, where T(n,k) = T(n,k-1) + (k+1)*T(n-1,k) for n>k>0, T(n,0)=1 and T(n,n) = T(n,n-1) for n>=0.at n=38A102316
- Start with 1027 and repeatedly reverse the digits and add 16 to get the next term.at n=2A119455
- Sums of three consecutive pentagonal numbers.at n=39A129863
- Indices k such that A020508(k)=Phi[k](-9) is prime, where Phi is a cyclotomic polynomial.at n=48A138921
- a(1) = 3, a(n + 1) = 1 + a(n) + least odd prime factor of a(n).at n=24A144751
- 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, 0, 0), (0, 0, 1), (0, 1, -1), (1, -1, 0)}.at n=10A148094
- a(n) = A014217(n+3) - A014217(n).at n=16A153263
- Number of binary strings of length n with no substrings equal to 0001 0110 or 1010.at n=14A164478