1643
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 14
- Digital Root
- 5
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 1728
- Proper Divisor Sum (Aliquot Sum)
- 85
- 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
- 1560
- Möbius Function
- 1
- Radical
- 1643
- 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
- 73
- 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) = 1000*log_10(n) rounded to the nearest integer.at n=43A004226
- Difference between A000294 and the number of solid partitions of n (A000293).at n=15A007326
- Expansion of (x^6-x^5-x^4+2x^2)/((1-x^3)(1-x^2)^2(1-x)).at n=44A007988
- Coordination sequence T2 for Zeolite Code AFS.at n=31A008024
- Coordination sequence T2 for Zeolite Code BPH.at n=31A008056
- Coordination sequence T1 for Zeolite Code LTN.at n=28A008140
- Coordination sequence T2 for Zeolite Code MEL.at n=26A008151
- Least m such that if a/b < c/d are Farey fractions of order n then there exists k such that a/b < k/m < c/d, k/m reduced.at n=46A009571
- Coordination sequence T3 for Zeolite Code -CHI.at n=26A009848
- Composite numbers that are equal to the sum of the first k composites for some k.at n=37A013921
- Coordination sequence T1 for Zeolite Code CGF.at n=28A019451
- Numbers k such that the period of the continued fraction for sqrt(k) contains exactly five 1's.at n=15A020441
- Numbers whose sum of divisors is a cube.at n=22A020477
- Numbers with exactly 3 3's in their base-5 expansion.at n=35A023736
- a(1) = 7; a(n+1) = a(n)-th composite.at n=19A025011
- a(n) = n^2 + n + 3.at n=40A027688
- a(n) = floor(10000/sqrt(n)).at n=36A033433
- Number of quaternary codes of length 3 with n words.at n=6A034234
- Number of quaternary codes (not necessarily linear) of length n with 6 words.at n=2A034243
- a(1)=1, a(n) = smallest odd number such that all sums of pairs of (not necessarily distinct) terms in the sequence are distinct.at n=24A034757