9720
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
- 1
Divisibility
- Divisor Count
- 48
- Divisor Sum
- 32760
- Proper Divisor Sum (Aliquot Sum)
- 23040
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Highly Composite
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 2592
- Möbius Function
- 0
- Radical
- 30
- Omega Function (Ω)
- 9
- 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
- yes
- Narcissistic Number
- no
- Collatz Steps
- 166
- Smith Number
- no
- Vampire Number
- no
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
- yes
- Carmichael Number
- no
Classification
- Even
- yes
- Odd
- no
Appears in sequences
- a(n) is least k such that k and 5k are anagrams in base n (written in base 10).at n=13A023097
- Number of reversible strings with n beads of 3 colors. If more than 1 bead, not palindromic.at n=8A032086
- One third of triple factorial numbers.at n=4A034001
- Triangle whose (i,j)-th entry is binomial(i,j)*3^(i-j)*6^j.at n=17A038224
- Triangle whose (i,j)-th entry is binomial(i,j)*6^(i-j)*3^j.at n=18A038257
- Number of 2n-bead balanced binary strings, rotationally equivalent to reversed complement, inequivalent to reverse and complement.at n=10A045660
- Numbers n such that 275*2^n-1 is prime.at n=20A050896
- Denominators of coefficients in function a(x) such that a(a(a(x))) = log (1+x).at n=4A052139
- Denominators of coefficients in function a(x) such that a(a(a(x))) = log (1+x).at n=5A052139
- Expansion of e.g.f. x*(1+x-3*x^2)/(1-3*x).at n=5A052690
- a(n) = 4 * A073120(n).at n=37A057102
- Triangle of congrua: T(n,k) = 4*n*k(n^2-k^2) with n>k>0 and starting at T(2,1) = 24. A055096(n)^2 + a(n) is a square, as is A055096(n)^2 - a(n).at n=33A057103
- Orders of finite perfect groups (groups such that G = G' where G' is the commutator subgroup of G).at n=40A060793
- When expressed in base 2 and then interpreted in base 9, is a multiple of the original number.at n=55A062850
- Numbers k such that sigma(k)+1 is a square and sets a new record for such squares.at n=32A063729
- Numbers k such that sigma(k) - usigma(k) > 2k.at n=22A063846
- a(n) = 3^n*n!*(n+2)!/2!.at n=3A064633
- Numbers k such that sigma(k) divides sigma(sigma(k)).at n=19A066961
- Numbers k such that 2^k mod phi(k) = 2^phi(k) mod k.at n=42A069050
- First differences of A069475, successive differences of (n+1)^6-n^6.at n=11A069476