6507
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 18
- Digital Root
- 9
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 9680
- Proper Divisor Sum (Aliquot Sum)
- 3173
- 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
- 4320
- Möbius Function
- 0
- Radical
- 723
- Omega Function (Ω)
- 4
- 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
- 49
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- no
- Squarefree Number
- no
- 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) = n*(9*n-2).at n=27A013656
- a(n) = (d(n)-r(n))/2, where d = A026063 and r is the periodic sequence with fundamental period (1,1,0,1).at n=32A026064
- Numbers whose base-5 representation contains exactly two 0's and three 2's.at n=28A045183
- Numbers k such that (k-1)*binomial(2k,k) + 1 is prime.at n=44A085793
- Sum of first n 4-almost primes.at n=39A086046
- Least number d such that 10^n -/+ 3d form a prime pair.at n=51A117738
- The sequence of numbers where the n-th term is (Pi^n - e^n) rounded down to the nearest integer, where Pi is the ratio of a circle's circumference to its diameter (A000796) and e is Euler's constant (A001113).at n=8A181052
- Number of (primitive) weird numbers of the form 2^n*p*q, with odd primes p < q.at n=14A258333
- Expansion of Product_{k>=1} (1 + (x + x^2)^k).at n=14A266108
- Permuted compound filter: a(n) = A286458(A064216(n)).at n=48A286459
- Numbers m such that there are precisely 13 groups of order m.at n=42A292896
- Number of nX3 0..1 arrays with each 1 adjacent to 3, 4 or 5 king-move neighboring 1s.at n=7A296985
- T(n,k)=Number of nXk 0..1 arrays with each 1 adjacent to 3, 4 or 5 king-move neighboring 1s.at n=47A296990
- T(n,k)=Number of nXk 0..1 arrays with each 1 adjacent to 3, 4 or 5 king-move neighboring 1s.at n=52A296990
- Number of integer partitions of n with at least two but not all parts having a common divisor greater than 1.at n=30A303139
- Number of perfect-power divisors of n!.at n=32A336416
- Odd composite integers m such that A054413(3*m-J(m,53)) == 7 (mod m), where J(m,53) is the Jacobi symbol.at n=40A340238
- Numbers k which are the product of a cube greater than 1 and a prime, and where k-1 and k-2 are semiprimes.at n=18A350284
- Inverse Mobius transformation of A034714.at n=37A360429
- Numbers k such that k and k+1 are both terms of A365883.at n=41A365884