1827
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
- 2
Divisibility
- Divisor Count
- 12
- Divisor Sum
- 3120
- Proper Divisor Sum (Aliquot Sum)
- 1293
- 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
- 1008
- Möbius Function
- 0
- Radical
- 609
- Omega Function (Ω)
- 4
- Little Omega Function (ω)
- 3
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
- 130
- Smith Number
- no
- Vampire Number
- yes
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
- Expansion of x^3*(5-2*x)*(1-x^3)/(1-x)^4.at n=19A000338
- Coefficients of Bell's formula for making change.at n=5A002575
- Coordination sequence T1 for Zeolite Code BRE.at n=28A008058
- Molien series for Weyl group E_7.at n=39A008583
- a(n) = floor(n*(n-1)*(n-2)/12).at n=29A011894
- a(n) = floor(n*(n-1)*(n-2)/30).at n=39A011912
- Vampire numbers (definition 2): numbers n with an even number of digits which have a factorization n = i*j where i and j have the same number of digits and the multiset of the digits of n coincides with the multiset of the digits of i and j.at n=4A014575
- Numbers k that divide s(k), where s(1)=1, s(j)=7*s(j-1)+j.at n=24A014854
- Odd numbers k that divide 25^k - 1.at n=26A014962
- Numbers k such that k | 5^k + 1.at n=22A015951
- Expansion of 1/(1-x^7-x^8-x^9-x^10-x^11-x^12-x^13).at n=48A017862
- Powers of cube root of 5 rounded down.at n=14A017988
- Concatenate cubes.at n=2A019522
- From George Gilbert's marks problem: jumping 4 marks at a time (initial positions).at n=14A019595
- Vampire numbers: (definition 1): n has a nontrivial factorization using n's digits.at n=10A020342
- Pisot sequence T(7,10), a(n) = floor(a(n-1)^2/a(n-2)).at n=26A020752
- Expansion of Molien series for 8-dimensional real Clifford group 2^{1+6}.Alt_8.2 of genus 3 and order 5160960.at n=35A024186
- Numbers having period-14 7-digitized sequences.at n=37A031205
- Lucky numbers with size of gaps equal to 8 (upper terms).at n=19A031891
- Lucky numbers ending with digit 7.at n=46A032588