6749
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 26
- Digital Root
- 8
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 7164
- Proper Divisor Sum (Aliquot Sum)
- 415
- 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
- 6336
- Möbius Function
- 1
- Radical
- 6749
- 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
- 44
- 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) = n*(n-1)*a(n-1)/2 + a(n-2), a(0) = a(1) = 1.at n=6A001046
- Idempotent semigroups of order n, considered to be equivalent when they are isomorphic or anti-isomorphic (by reversal of the operator).at n=7A002788
- Numbers k such that the continued fraction for sqrt(k) has period 9.at n=35A010339
- Number of partitions of n into parts not of the form 21k, 21k+6 or 21k-6. Also number of partitions with at most 5 parts of size 1 and differences between parts at distance 9 are greater than 1.at n=32A035984
- a(n) = Fibonacci(n) OR Fibonacci(n+1).at n=18A051123
- Discriminants of real quadratic fields with class number 2 and related continued fraction period length of 15.at n=12A051980
- Numbers k such that k^14 == 1 (mod 15^3).at n=7A056087
- Triangle read by rows: semigroups of order n with k idempotents, considered to be equivalent when they are isomorphic or anti-isomorphic (by reversal of the operator).at n=27A058123
- Composite and every divisor (except 1) contains the digit 7.at n=30A062676
- Number of partitions of n into sums of products.at n=24A066815
- Interprimes which are of the form s*prime, s=17.at n=5A075292
- Main diagonal of A101866.at n=42A101867
- Numerators of partial sums of (p+q)/p*q, where p and q are primes.at n=8A120831
- Odd interprimes divisible by 17.at n=24A124620
- Half-sum (or average) of cubes of two distinct odd primes.at n=24A138855
- Numbers k such that the continued fraction of (1 + sqrt(k))/2 has period 15.at n=31A146338
- Numerator of Euler(n, 1/19).at n=3A156656
- a(n) = 225*n - 1.at n=29A158227
- a(n) = 30*n^2 - 1.at n=14A158560
- Numerator of A166100(A166101(n))/A166102(n).at n=21A166272