7288
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 25
- Digital Root
- 7
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 4
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 13680
- Proper Divisor Sum (Aliquot Sum)
- 6392
- 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
- 3640
- Möbius Function
- 0
- Radical
- 1822
- Omega Function (Ω)
- 4
- 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
- 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
- no
- Carmichael Number
- no
Classification
- Even
- yes
- Odd
- no
Appears in sequences
- Absolute value of Glaisher's alpha(n).at n=19A002290
- Expansion of e.g.f.: log(1 + tanh(x)*exp(x)).at n=8A009395
- Numbers k such that k | 7^k + 7.at n=23A015893
- a(n) = 2*a(n-1) + a(floor(n/2)), with a(1) = 1, a(2) = 2, a(3) = 4.at n=12A033497
- Composite n such that phi(n+4) = phi(n)+4.at n=42A056773
- Number of palindromes (in base 9) below 9^n.at n=6A117868
- Triangle T(n,k) read by rows: number of permutations in [n] with exactly k ascents that have an even number of inversions.at n=38A128612
- Triangle T(n,k) read by rows: number of permutations in [n] with exactly k ascents that have an even number of inversions.at n=42A128612
- Numbers k whose representation can be split in two parts which can be used as seeds for a Fibonacci-like sequence containing k itself.at n=45A130792
- Triangle read by rows: T(n,k) is the number of even permutations of {1,2,...,n} having k descents (n >= 1, k >= 0).at n=34A145882
- Triangle read by rows: T(n,k) is the number of even permutations of {1,2,...,n} having k descents (n >= 1, k >= 0).at n=38A145882
- Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, -1, 1), (0, 0, 1), (0, 1, -1), (1, 0, -1), (1, 1, 0)}.at n=7A150463
- G.f.: (1-2*x-5*x^2+4*x^3)/((1-4*x)*(1-x)^2).at n=7A151746
- Number of ways to place n nonattacking composite pieces queen + rider[1,4] on an n X n chessboard.at n=14A189874
- Numbers k such that the trajectory of 3k + 1 under the '3x + 1' map reaches k.at n=34A219696
- a(2)=9; thereafter a(n) = smallest number m such that a(n-1)+m = (a(n-1) followed by the leading digit of m).at n=3A224760
- G.f.: Product_{k>0} (1 - x^k)^4 * (1 - (-x)^k)^8.at n=19A225543
- Number of partitions of n, where the difference between the number of odd parts and the number of even parts is 2.at n=44A240011
- Number of partitions of n with difference -9 between the number of odd parts and the number of even parts, both counted without multiplicity.at n=34A242683
- Consider a number x as a concatenation of two integers, a and b: x = concat(a,b). Take their sum and repeat the process deleting the minimum number and adding the previous sum. The sequence lists the numbers that after some iterations reach a sum equal to themselves.at n=40A248134