1826
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 17
- Digital Root
- 8
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 4
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 3024
- Proper Divisor Sum (Aliquot Sum)
- 1198
- 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
- 1826
- Omega Function (Ω)
- 3
- 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
- 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 topologies on n labeled points satisfying axioms T_0-T_4.at n=5A006057
- Log of g.f. of numbers of preferential arrangements.at n=6A006989
- 10-gonal (or decagonal) pyramidal numbers: a(n) = n*(n + 1)*(8*n - 5)/6.at n=11A007585
- Coordination sequence for quartz.at n=24A008261
- Expansion of (1+x^9)/((1-x)*(1-x^2)*(1-x^3)*(1-x^4)).at n=50A008770
- Coordination sequence T1 for Zeolite Code VSV.at n=27A009914
- Coordination sequence T2 for Zeolite Code WEI.at n=31A009918
- Numbers k such that phi(k) | sigma_10(k).at n=13A015768
- Coordination sequence T7 for Zeolite Code TER.at n=29A016439
- Expansion of 1/(1-x^10-x^11-x^12-x^13-x^14).at n=76A017890
- Expansion of 1/(1 - x^11 - x^12 - ...).at n=61A017905
- a(n) = 2*a(n-1) + a(n-2) - a(n-4) - a(n-5) - a(n-6) - a(n-7).at n=8A019486
- a(n) = 1*t(n) + 2*t(n-1) + ... + k*t(n+1-k), where k=floor((n+1)/2) and t(n)=2*n+1 (odd numbers).at n=20A023865
- a(n) = a(1)*a(n-1) + a(2)*a(n-2) + ... + a(n-3)*a(3) for n >= 4, with initial terms 1, 0, 2, 2.at n=12A025248
- Index of 10^n within the sequence of the numbers of the form 3^i*10^j.at n=41A025741
- Expansion of (2 + x + x^2)/((1 - x)*(1 - x - x^2)).at n=12A026390
- Numbers k such that the continued fraction for sqrt(k) has even period and if the last term of the periodic part is deleted the central term is 42.at n=5A031540
- Concatenation of n and n + 8 or {n,n+8}.at n=17A032613
- Numbers with the property that all pairs of consecutive base-4 digits differ by more than 1.at n=43A032967
- Number of days in n years (n=4 is the first leap year).at n=4A033171