7165
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
- 2
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 8604
- Proper Divisor Sum (Aliquot Sum)
- 1439
- 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
- 5728
- Möbius Function
- 1
- Radical
- 7165
- 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
- 101
- 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
- Number of 5th-order maximal independent sets in path graph.at n=50A007380
- Numbers k such that the continued fraction for sqrt(k) has period 73.at n=2A020412
- Numbers k such that the continued fraction for sqrt(k) has odd period and if the last term of the periodic part is deleted then there are a pair of central terms both equal to 7.at n=18A031420
- Expansion of (1+2*x-3*x^2-4*x^3+x^4)/(1-8*x^2+11*x^4).at n=10A033482
- First differences of A037260.at n=28A037261
- Sums of 11 distinct powers of 2.at n=31A038462
- Numbers whose base-4 representation contains exactly two 1's and four 3's.at n=34A045123
- a(n) = a(n-1) + a(m) for n >= 3, where m = 2^(p+1) + 2 - n and p is the unique integer such that 2^p < n - 1 <= 2^(p+1), starting with a(1) = 1 and a(2) = 2.at n=46A050049
- Numbers n such that mu(n) + mu(n+1) + mu(n+2) + mu(n+3) + mu(n+4) + mu(n+5) + mu(n+6) = 6.at n=6A082967
- Numbers k such that each of k through k+4 are divisible by exactly two primes.at n=44A088986
- a(n) = Sum_{k=0..floor(n/7)} C(n-5*k,2*k).at n=29A098574
- Irregular array where the n-th row are the divisors, not occurring earlier in the sequence, of the sum of the terms in all previous rows. a(1)=5.at n=29A120579
- The number of edges on a piece of paper that has been folded n times (see comments for more precise definition).at n=20A133257
- a(0) = a(1) = 1. a(n) = Sum_{p|n} a(n-p), where the sum is over all distinct primes p that divide n.at n=54A134192
- Number of planar triangular n X n X n nonnegative integer grids with mirror symmetry about one altitude with every similarly oriented 5 X 5 X 5 subtriangle summing to 8.at n=3A154071
- a(n) = 7*2^n - 3.at n=10A156127
- a(n) = Fibonacci(n) + n^2.at n=20A160536
- a(n)=a(n-1)+2*a(n-2)-[a(n-1)/2]-[a(n-4)/2]-[a(n-5)/2].at n=19A173534
- Upper Beatty array of the golden ratio, (1+sqrt(5))/2.at n=28A181661
- Number of nX6 0..1 arrays avoiding 0 0 0 and 0 1 1 horizontally and 0 0 1 and 0 1 0 vertically.at n=3A207240