6530
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 14
- Digital Root
- 5
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 11772
- Proper Divisor Sum (Aliquot Sum)
- 5242
- 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
- 2608
- Möbius Function
- -1
- Radical
- 6530
- Omega Function (Ω)
- 3
- Little Omega Function (ω)
- 3
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
- yes
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 137
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- no
- 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
- Coordination sequence T2 for Keatite.at n=45A009845
- Numbers k such that the continued fraction for sqrt(k) has period 9.at n=34A010339
- Dying rabbits: a(n) = a(n-1) + a(n-2) - a(n-11).at n=20A023441
- Positions of A080313 in A014486.at n=18A080312
- Total height of all elements in all preferential arrangements of n elements, where elements at the bottom level have height 1.at n=4A083385
- Numbers m such that the numerator of Sum_{i=1..m} (i-1)/i is prime.at n=49A091815
- Numbers k such that 5*R_k + 4 is prime, where R_k = 11...1 is the repunit (A002275) of length k.at n=12A099418
- Numbers k such that k + sigma(k) + phi(k) is a triangular number.at n=34A115906
- Pendular triangle, read by rows, where row n is formed from row n-1 by the recurrence: if n > 2k, T(n,k) = T(n,n-k) + T(n-1,k), else T(n,k) = T(n,n-1-k) + 3*T(n-1,k), for n>=k>=0, with T(n,0)=1 and T(n,n)=0^n.at n=71A118350
- Semi-diagonal (one row below central terms) of pendular triangle A118350 and equal to the self-convolution of the central terms (A118351).at n=5A118352
- Convolution triangle, read by rows, where diagonals are successive self-convolutions of A118351.at n=33A118354
- a(0)=1; for n > 0, a(n) = a(n-1) + a(prime(n)(mod n)), where prime(n) is the n-th prime.at n=31A127066
- 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, 1), (1, 0, 0), (1, 1, -1), (1, 1, 0)}.at n=7A150369
- Number of nondecreasing arrangements of 6 numbers x(i) in -(n+4)..(n+4) with the sum of sign(x(i))*2^|x(i)| zero.at n=23A187990
- Number of right triangles on an (n+1) X 3 grid.at n=30A189807
- Expansion of 1 / (1 - x - x^3 + x^6) in powers of x.at n=31A193771
- a(n) is the conjectured highest power of n which has no four identical digits in succession.at n=25A216065
- Numbers which are the sum of two squared primes in exactly two ways (ignoring order).at n=35A226539
- Related to Pisano periods: numbers n such that there are n+10 distinct Fibonacci numbers mod n.at n=20A229467
- Number of (n+1)X(2+1) 0..2 arrays with every 2X2 subblock diagonal maximum minus antidiagonal maximum unequal to its neighbors horizontally and vertically.at n=1A253726