7290
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
- 28
- Divisor Sum
- 19674
- Proper Divisor Sum (Aliquot Sum)
- 12384
- 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
- 1944
- Möbius Function
- 0
- Radical
- 30
- Omega Function (Ω)
- 8
- 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
- 44
- 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
- Expansion of g.f.: (1+x)/(1-9*x).at n=4A003952
- a(n) = 10*3^n.at n=6A005052
- a(n) = n*3^(n-4).at n=7A006234
- Denominators of generalized Bernoulli numbers.at n=8A006568
- a(n) = floor(n/4)*floor((n+1)/4)*floor((n+2)/4)*floor((n+3)/4).at n=37A008233
- Triangle of coefficients in expansion of (1+9x)^n.at n=18A013616
- Triangle of coefficients in expansion of (3+5x)^n.at n=22A013622
- Numbers of form 3^i*10^j, with i, j >= 0.at n=21A025616
- Numbers of form 9^i*10^j, with i, j >= 0.at n=11A025635
- Sums of distinct powers of 9.at n=24A033046
- a(n) = 10*n^2.at n=27A033583
- Theta series of lattice A_2 tensor E_6 (dimension 12, det. 6561, min. norm 4).at n=4A033698
- Number of partitions of n with equal number of parts congruent to each of 0 and 4 (mod 5).at n=38A035555
- Positive numbers having the same set of digits in base 2 and base 9.at n=20A037414
- Triangle whose (i,j)-th entry is binomial(i,j)*5^(i-j)*3^j.at n=26A038245
- Triangle whose (i,j)-th entry is binomial(i,j)*9^(i-j)*1^j.at n=17A038291
- Sums of 2 distinct powers of 3.at n=34A038464
- Sums of two distinct powers of 9.at n=9A038487
- Triangular matrix arising in enumeration of catafusenes, read by rows.at n=43A038763
- Numerators of continued fraction convergents to sqrt(915).at n=2A042768