6865
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 25
- Digital Root
- 7
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 8244
- Proper Divisor Sum (Aliquot Sum)
- 1379
- 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
- 5488
- Möbius Function
- 1
- Radical
- 6865
- 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
- 150
- 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) is the solution to the postage stamp problem with 5 denominations and n stamps.at n=16A001210
- Self-convolution of Fibonacci numbers.at n=16A001629
- a(n) = 1 + n/2 + 9*n^2/2.at n=39A006137
- Numbers k such that the continued fraction for sqrt(k) has period 51.at n=9A020390
- Least k such that A033178(k)=n.at n=37A038004
- Same rule as Aitken triangle (A011971) except a(0,0)=1, a(1,0)=0.at n=43A046934
- Sequence formed from rows of triangle A046934.at n=34A046935
- Even-indexed terms of A001629(n), n >= 2, (Fibonacci convolution).at n=7A054444
- Number of points in Z^n of norm <= 2.at n=11A055426
- Bisection of Fibonacci triangle A037027: even-indexed members of column sequences of A037027 (not counting leading zeros).at n=37A060920
- Centered 13-gonal numbers.at n=32A069126
- a(n) = n^3 + 6.at n=19A084382
- Semiprimes in A056106.at n=17A113524
- Numbers with composite sum of digits and prime sum of cubes of digits.at n=33A121642
- Number of 2 X 2 singular integer matrices with elements from {1,...,n}.at n=41A134506
- a(n) = (p(n)*p(n+2) - p(n+1))/2, where p(n) is the n-th odd prime.at n=27A152531
- a(n) = prime(n) * prime(n+2) - 2 * prime(n+1).at n=21A152532
- a(n) = 12*n^2 + 22*n + 11.at n=23A154106
- Positive numbers y such that y^2 is of the form x^2+(x+2401)^2 with integer x.at n=10A157247
- Number of binary strings of length n with no substrings equal to 0001 0110 or 1101.at n=14A164481