6381
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
- 3
Divisibility
- Divisor Count
- 6
- Divisor Sum
- 9230
- Proper Divisor Sum (Aliquot Sum)
- 2849
- 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
- 4248
- Möbius Function
- 0
- Radical
- 2127
- 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
- Largest number not the sum of distinct n-th-order polygonal numbers.at n=23A007419
- (n+1) * a(n+1) - 2 (68*n^2+68*n+27) * a(n) + 6 * n * (772*n^2+35) * a(n-1) - 2 * (2*n-1)^2 * (68*n^2-68*n+27) * a(n-2) + (2*n-1)^2 * (n-1) * (2*n-3)^2 * a(n-3) = 0.at n=2A007761
- Reverse or triple: if reverse(a(n)) > a(n), a(n+1) = reverse(a(n)), else a(n+1) = 3*a(n).at n=8A042938
- Number of commutative quasigroups of order n.at n=7A057992
- a(n) = sigma[k](n) - phi(n)^k - d(n)^k for k=3.at n=17A079539
- Numbers n such that n*nextprime((n-1)!)-nextprime(n!) < 0.at n=16A090660
- a(n) = (15*n^2 + 5*n + 2)/2.at n=28A093500
- a(n) = smallest number greater than a(n-1) having a largest proper divisor that is greater than and coprime to a(n-1); a(1) = 1.at n=30A098144
- Start with 1 and repeatedly reverse the digits and add 50 to get the next term.at n=34A118147
- a(n) is the number of nonnegative integers k less than 10^n such that the decimal representation of k lacks the digit 1, at least one of digits 2,3,4 and at least one of digits 5,6,7,8,9.at n=3A125910
- Ulam's spiral (NNW spoke).at n=20A143860
- Number of ways to place zero or more nonadjacent 1,1 2,1 3,0 3,1 4,2 4,3 5,2 6,2 polyhexes in any orientation on a planar nXnXn triangular grid.at n=7A155394
- Triple and reverse digits.at n=5A163632
- Number of partitions of n such that all parts are equal or all parts are distinct.at n=55A167932
- T(n,k) = 4*A046802(n,k) - 3*A007318(n,k), triangle read by rows (0 <= k <= n).at n=30A168289
- T(n,k) = 4*A046802(n,k) - 3*A007318(n,k), triangle read by rows (0 <= k <= n).at n=33A168289
- Integers n such that 17+30*n are terms in A172456.at n=8A175103
- Triangle of coefficients of polynomials u(n,x) jointly generated with A209764; see the Formula section.at n=51A209763
- Number of (w,x,y) with all terms in {0,...,n} and 2|w-x| >= max(w,x,y)-min(w,x,y).at n=20A213388
- Triangle read by rows, T(n,k) for 0<=k<=n, generalizing A098742.at n=29A216916