8135
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 17
- Digital Root
- 8
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 9768
- Proper Divisor Sum (Aliquot Sum)
- 1633
- 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
- 6504
- Möbius Function
- 1
- Radical
- 8135
- 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
- 65
- 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
- Central pentanomial coefficients: largest coefficient of (1 + x + ... + x^4)^n.at n=7A005191
- a(n) = [ a(n-1)/a(1) ] + [ a(n-2)/a(2) ] + ... + [ a(1)/a(n-1) ], for n >= 3.at n=20A022864
- T(n,n+3), array T given by A047020.at n=7A047028
- Column 3 of triangle A055898.at n=9A055899
- Interprimes which are of the form s*prime, s=5.at n=19A075280
- Numbers k such that k, k+2, k+4, k+6, k+8 are semiprimes.at n=26A092127
- Numbers k such that k^4 = x^3 + y^2 has an integer solution.at n=31A096741
- Numbers n such that the partition function A000041(k) is even and odd the same number of times for 0 <= k <= n.at n=17A098936
- Triangular matrix T, read by rows, that satisfies: SHIFT_LEFT(column 0 of T^p) = p*(column p+1 of T), or [T^p](m,0) = p*T(p+m,p+1) for all m>=1 and p>=-1.at n=39A104980
- Column 3 of triangle A104980, omitting leading zeros.at n=5A104982
- Numbers n such that (2^p + 1)/3 is prime, where p is the n-th prime.at n=30A123176
- Numbers n such that A117731(n) differs from A082687(n).at n=43A125740
- Expansion of f(-x, -x^7) / f(-x, -x) in powers of q where f(, ) is Ramanujan's general theta function.at n=27A132212
- The size of the largest antichain in the 7-dimensional hypercubic lattice of size n; also the coefficient of x^floor(7*(n-1)/2) in (1 + x + ... + x^(n-1))^7.at n=4A133458
- a(1)=1, a(n)=a(n-1)+n^3 if n odd, a(n)=a(n-1)+ n^0 if n is even.at n=14A140152
- Totally multiplicative sequence with a(p) = a(p-1) + 7 for prime p.at n=28A166704
- Number of inequivalent ways to select n cards in the game of SET.at n=11A182240
- Number of 0..n arrays x(0..3) of 4 elements without any interior element greater than both neighbors or less than both neighbors.at n=13A200872
- Square array read by diagonals: T(n,k) = number of arrays of n integers in -k..k with sum equal to 0.at n=34A201552
- Number of arrays of 7 integers in -n..n with sum zero.at n=2A201554