8471
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
- 4
- Divisor Sum
- 8712
- Proper Divisor Sum (Aliquot Sum)
- 241
- 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
- 8232
- Möbius Function
- 1
- Radical
- 8471
- 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
- yes
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 57
- 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
- a(n) = [ a(n-1)/a(1) + a(n-3)/a(3) + a(n-5)/a(5) + ... ], for n >= 3.at n=36A022871
- Numbers whose set of base-14 digits is {1,3}.at n=24A032921
- Triangle T(n,k) of numbers with e.g.f. exp((exp((1+x)*y)-1)/(1+x)), k=0..n-1.at n=32A059340
- Second 11-gonal (or hendecagonal) numbers: a(n) = n*(9*n+7)/2.at n=43A062728
- Numbers k such that Euler phi(k) / Carmichael lambda(k) = 14.at n=17A066696
- Right diagonal of triangle in A110339.at n=42A110341
- a(n) = 11 + floor((2 + Sum_{j=1..n-1} a(j))/3).at n=23A120156
- a(n) = least k such that the remainder of 30^k divided by k is n.at n=4A128370
- a(n) = a(n) = +13*a(n-2) +7*a(n-3) -47*a(n-4) -38*a(n-5) +48*a(n-6) +43*a(n-7) -7*a(n-8) -1*a(n-9).at n=7A134325
- Numbers k such that k and k^2 use only the digits 1, 4, 5, 7 and 8.at n=6A137049
- Numbers k such that k^81*(k^81+1)+1 is prime.at n=38A153442
- a(n) = 242*n + 1.at n=34A157958
- a(n) = 70*n^2 + 1.at n=11A158734
- Triangle read by rows: T(n,k) is the number of involutions of {1,2,...,n} having k descents (n >= 1; 0 <= k < n).at n=59A161126
- Triangle read by rows: T(n,k) is the number of involutions of {1,2,...,n} having k descents (n >= 1; 0 <= k < n).at n=61A161126
- Generalized Lucas numbers: a(n) = a(n-1) + 10*a(n-2); with a(1)=2 a(2)=1.at n=7A164827
- a(n) = the smallest positive integer that, when written in binary, contains both binary n and binary n^2 as substrings.at n=22A165820
- Numbers that are the product of two distinct primes a and b, such that a^3+b^3 is the average of a twin prime pair.at n=29A176876
- Let f(m) = number of steps needed to reach a Harshad number when the map k->A062028(l) is iterated starting at m; a(n) = smallest m such that f(m) = n.at n=80A181664
- Integers n such that for all i > n the largest prime factor of product(i+k, {k,0,10}) exceeds the largest prime factor of product(n+k, {k,0,10}).at n=20A200568