6345
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
- 2
Divisibility
- Divisor Count
- 16
- Divisor Sum
- 11520
- Proper Divisor Sum (Aliquot Sum)
- 5175
- 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
- 3312
- Möbius Function
- 0
- Radical
- 705
- Omega Function (Ω)
- 5
- 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
- 80
- 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
- Dying rabbits: a(n) = a(n-1) + a(n-2) - a(n-10).at n=20A023440
- Number of perfect matchings in graph P_{2} X C_{4} X P_{n}.at n=3A028456
- Number of perfect matchings in graph P_{3} X C_{4} X P_{n}.at n=2A028461
- Lucky numbers with size of gaps equal to 14 (upper terms).at n=31A031897
- Number of partitions of n with equal nonzero number of parts congruent to each of 1, 3 and 4 (mod 5).at n=55A035590
- Number of partitions satisfying cn(0,5) < cn(1,5) + cn(4,5) + cn(2,5) and cn(0,5) < cn(1,5) + cn(4,5) + cn(3,5).at n=30A039846
- Numbers k such that 157*2^k-1 is prime.at n=13A050830
- 20-gonal (or icosagonal) numbers: a(n) = n*(9*n-8).at n=27A051872
- Numbers k such that k | 5^k + 4^k + 3^k + 2^k + 1^k.at n=35A056741
- a(n) = 3*n^2 + 6*n.at n=45A067725
- a(n) = sum of absolute values of coefficients of (1+x-3x^2)^n.at n=6A084615
- Triangle T(n, k) read by rows; given by [1, 1, 1, 1, 1, 1, 1, 1, ...] DELTA [1, 0, 2, 0, 2, 0, 3, 0, 2, 0, 4, 0, 2, 0, ...] (A000005 interspersed with 0's) where DELTA is Deléham's operator defined in A084938.at n=31A085853
- Structured pentagonal icositetrahedral numbers (vertex structure 13).at n=8A100167
- Square array T(n,d) read by antidiagonals: number of structurally-different guillotine partitions of a d-dimensional box in R^d by n hyperplanes.at n=32A103209
- Triangle related to guillotine partitions of a k-dimensional box by n hyperplanes.at n=40A107702
- Non-cubefree numbers k such that 2k+1 is also non-cubefree (A046099).at n=45A115170
- a(n) = 5*n + 3^n - 2^n.at n=8A120849
- Numbers n such that (n+2) | (2^n+3^n).at n=5A123049
- Composite numbers k that divide 3^k - 2^k - 1, excluding powers of 2, 3 and 7.at n=19A127073
- a(n) = (1/n)*Sum_{i=0..n-1} C(n,i)*C(n,i+1)*4^i*5^(n-i), a(0) = 1.at n=4A133305