1642
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 13
- Digital Root
- 4
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 2466
- Proper Divisor Sum (Aliquot Sum)
- 824
- 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
- 820
- Möbius Function
- 1
- Radical
- 1642
- 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
- 29
- Smith Number
- yes
- 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
- yes
- Odd
- no
Appears in sequences
- Number of (undirected) Hamiltonian paths in the n-ladder graph K_2 X P_n.at n=40A003682
- Coordination sequence T4 for Zeolite Code AET.at n=28A008010
- Coordination sequence T1 for Zeolite Code AFS.at n=31A008023
- Coordination sequence T1 for Zeolite Code BPH.at n=31A008055
- Coordination sequence T3 for Zeolite Code MEP.at n=24A008159
- Coordination sequence T2 for Zeolite Code MFS.at n=25A008174
- Coordination sequence for tridymite, lonsdaleite, and wurtzite.at n=25A008264
- "Pascal sweep" for k=6: draw a horizontal line through the 1 at C(k,0) in Pascal's triangle; rotate this line and record the sum of the numbers on it (excluding the initial 1).at n=53A009475
- Coordination sequence T3 for Zeolite Code iRON.at n=28A009883
- Coordination sequence T1 for Zeolite Code RTH.at n=28A009893
- Coordination sequence T7 for Zeolite Code VNI.at n=25A009913
- a(n) = n^2 + n + 2.at n=40A014206
- Powers of fifth root of 5 rounded to nearest integer.at n=23A018127
- Powers of fifth root of 5 rounded up.at n=23A018128
- Numbers k such that the continued fraction for sqrt(k) has period 29.at n=3A020368
- a(n) = least m such that if r and s in {h/(1 + h^2): h = 1,2,...,n} satisfy r < s, then r < k/m < s for some integer k.at n=45A024828
- Numbers k such that 163*2^k+1 is prime.at n=28A032458
- Coordination sequence T4 for Zeolite Code SBS.at n=32A033611
- Number of partitions of n with equal nonzero number of parts congruent to each of 1, 2 and 4 (mod 5).at n=48A035589
- Number of partitions of n such that cn(3,5) < cn(0,5) = cn(1,5) < cn(2,5) = cn(4,5).at n=64A036877