7285
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 22
- Digital Root
- 4
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 9216
- Proper Divisor Sum (Aliquot Sum)
- 1931
- 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
- 5520
- Möbius Function
- -1
- Radical
- 7285
- 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
- 44
- 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
- no
- Odd
- yes
Appears in sequences
- Convolved Fibonacci numbers.at n=8A001873
- a(n) = floor( exp(7/19)*n! ).at n=6A030871
- a(n) = max T(n,k), with T as in A037027.at n=12A038149
- Revert transform of 2*x*(1 - x + x^2 - x^3 + x^4 - x^5)-x/(1+x).at n=13A049181
- Numerators of successive convergents to continued fraction 1+2/(3+3/(4+4/(5+5/(6+6/(7+7/(8+8/(9+9/10+...))))))).at n=5A053518
- Number of binary vectors (x_1,...x_n) satisfying Sum_{i=1..n} i*x_i = 3 (mod n+1) = size of Varshamov-Tenengolts code VT_3(n).at n=17A054200
- Bisection of Fibonacci triangle A037027: even-indexed members of column sequences of A037027 (not counting leading zeros).at n=40A060920
- Fifth column (m=4) of triangle A060920 (bisection of Fibonacci triangle, even part).at n=4A061180
- Numbers n such that zero is never reached by iterating the mapping k -> abs(reverse(lpd(k))-reverse(gpf(k))). lpd(k) is the largest proper divisor and gpf(k) is the largest prime factor of k.at n=19A076425
- Fourth column (m=3) of (1,6)-Pascal triangle A096956.at n=29A096957
- Number of compositions of n in which the smallest part is equal to the number of parts.at n=42A098133
- Triangle read by rows: T(n,k) is the number of hill-free Dyck paths of semilength n and having k peaks at odd levels (0<=k<=n-2; n>=2). A hill in a Dyck path is a peak at level 1.at n=47A114586
- Riordan matrix (1/(1-x-x^2),x/(1-x-x^2)^2).at n=57A152440
- Equal to A171368*A007318.at n=68A171839
- a(n) = 2^m minus (the total number of distinct subsets of length-(m-n) binary words that can appear as the factor of a word of length m, for 0 <= n < m/2).at n=11A225865
- Number of partitions of n not containing the number of distinct parts as a part.at n=34A239946
- Quasi-Carmichael numbers to at least one positive base.at n=38A259283
- Number of length n arrays of permutations of 0..n-1 with each element moved by -3 to 3 places and every four consecutive elements having its maximum within 4 of its minimum.at n=19A263712
- Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 147", based on the 5-celled von Neumann neighborhood.at n=22A270292
- Number of sequences of balls colored with at most n colors such that exactly three balls are the same color as some other ball in the sequence.at n=4A292998