6419
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 20
- Digital Root
- 2
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 6
- Divisor Sum
- 7524
- Proper Divisor Sum (Aliquot Sum)
- 1105
- 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
- 5460
- Möbius Function
- 0
- Radical
- 917
- Omega Function (Ω)
- 3
- 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
- 75
- 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
- Number of partitions of 2n with all subsums different from n.at n=21A006827
- Cycle class sequence c(2n) (the number of true cycles of length 2n in which a certain node is included) for zeolite ABW = Li-A (Barrer and White).at n=5A018940
- Numbers k such that 27*2^k+1 is prime.at n=26A032363
- Number of partitions satisfying cn(1,5) + cn(4,5) <= cn(0,5) + cn(2,5) and cn(1,5) + cn(4,5) <= cn(0,5) + cn(3,5).at n=38A039864
- Number of polypons with n cells.at n=15A057784
- a(1)=1, a(n)=2a(n-1)+1 if a(n-1) is prime, a(n)=a(n-1)+1 otherwise.at n=42A083005
- a(n) = round(10000*log(n/10)).at n=18A104077
- Expansion of x*(1-3*x)*(1-x)/(1-7*x+14*x^2-7*x^3).at n=7A122068
- Numbers k such that 3*k+2, 4*k+3 and 5*k+4 are primes.at n=41A126956
- Positive integers whose sixth power is the sum of seven sixth powers (smallest primitive solutions).at n=36A132410
- Odd composite numbers such that the sum of any two terms, plus 1, is composite.at n=33A133763
- a(n) is the smallest positive multiple of 2n-1 that contains the binary representation of n in its binary representation and that is a palindrome when written in binary.at n=24A158789
- Irregular triangle read by rows: T(n,k), n >= 2, 1 <= k <= n/2, = number of rooted forests with n nodes and k trees, with at least two nodes in each tree.at n=37A174135
- Number of 0..n arrays x(0..7) of 8 elements with zero 5th differences.at n=17A200275
- Number of third differences of arrays of length n+3 of numbers in 0..4.at n=2A228256
- T(n,k)=Number of third differences of arrays of length n+3 of numbers in 0..k.at n=17A228260
- Number of third differences of arrays of length 6 of numbers in 0..n.at n=3A228262
- a(n) is the minimum number greater than a(n-1) such that the concatenation a(n) U a(n-1) U ... U a(1) is a Niven number, starting with a(1)=1.at n=32A239543
- a(n) = ( 2*n*(2*n^2 + 9*n + 14) + (-1)^n - 1 )/16.at n=28A248851
- Working in binary, write n followed by 0 then n-reversed (including leading zeros); show result in base 10.at n=50A264618