8418
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 21
- Digital Root
- 3
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 16
- Divisor Sum
- 17856
- Proper Divisor Sum (Aliquot Sum)
- 9438
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Highly Composite
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 2640
- Möbius Function
- 1
- Radical
- 8418
- Omega Function (Ω)
- 4
- Little Omega Function (ω)
- 4
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
- 34
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- no
- 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
- yes
- Odd
- no
Appears in sequences
- Number of trees in an n-node wheel.at n=20A002985
- Number of necklaces with n beads of 3 colors, allowing turning over.at n=11A027671
- a(n) = n*(4*n-1).at n=46A033991
- Sum{T(i,n-i): i=0,1,...,n}, array T as in A047100.at n=14A047101
- Smallest value of x such that M(x) = n, where M() is Mertens's function A002321.at n=25A051400
- Geometric mean of the digits = 4. In other words, the product of the digits is = 4^k where k is the number of digits.at n=38A061428
- Integers n > 7059 such that the 'Reverse and Add!' trajectory of n joins the trajectory of 7059.at n=14A063058
- a(n) = A064842(n)/2.at n=36A064843
- a(n) = floor(concatenation of first n primes / sum of first n primes).at n=4A067110
- Numbers k such that prime(k+2)-(k+2)*tau(k+2) = prime(k-2)-(k-2)*tau(k-2) where tau(k) = A000005(k) is the number of divisors of k.at n=27A067354
- a(n) = Sum_{i=n+1..2n} i^n.at n=3A074209
- Triangular array related to tennis ball problem, read by rows.at n=61A079521
- a(n) = number of primes of the form x^2 + 1 <= 2^n.at n=33A083847
- a(n) = Sum {j=1..n} j*A001462(j).at n=41A143125
- 3 times 13-gonal (or tridecagonal) numbers: a(n) = 3*n*(11*n - 9)/2.at n=23A153875
- Number of planar triangular n X n X n nonnegative integer grids with mirror symmetry about one altitude with every similarly oriented 5 X 5 X 5 subtriangle summing to 13.at n=13A154089
- a(n) = 4*n^2 + 79*n + 390.at n=35A157434
- a(n) = 16*n^2 - 2*n.at n=22A158058
- a(n) = 4*n^4 + 24*n^3 + 84*n^2 + 144*n + 98.at n=5A160828
- Sum_{j=k(n)..prime(n)} j where k is the n-th nonprime nonnegative integer.at n=32A161669