7544
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 20
- Digital Root
- 2
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 16
- Divisor Sum
- 15120
- Proper Divisor Sum (Aliquot Sum)
- 7576
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Highly Composite
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- yes
Derived Values
- Euler's Totient
- 3520
- Möbius Function
- 0
- Radical
- 1886
- Omega Function (Ω)
- 5
- 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
- 39
- 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
- Numbers k such that sigma(k) = sigma(k+10).at n=17A015880
- a(n) = n*(9*n - 1)/2.at n=41A022266
- Number of partitions of n into parts not of the form 9k, 9k+4 or 9k-4. Also number of partitions with at most 3 parts of size 1 and differences between parts at distance 3 are greater than 1.at n=41A035943
- Triangle T(n, k) giving coefficients in expansion of n! * Sum_{i=0..n} binomial(x - n, i) in powers of x.at n=19A054649
- a(1) = 1 and for n > 1 let a(n) = a(n-1) + m, where m is the arithmetic mean of the largest subset of all predecessors such that m is an integer and m is maximal.at n=31A063676
- Analogous to the oblong (promic or heteromecic) sequence formed but with reversal digits of factors multiplied.at n=27A102069
- Numbers k such that 12*k - 5, 12*k - 1, 12*k + 1, and 12*k + 5 are primes.at n=35A174372
- Numbers with abundance 32.at n=2A175989
- Number of permutations of 4..n+3 with no element greater than or equal to the sum of its neighbors.at n=7A180892
- Inverse permutation to A190134.at n=6A190135
- Triangle of coefficients of polynomials u(n,x) jointly generated with A210601; see the Formula section.at n=41A210600
- Number of (w,x,y,z) with all terms in {0,...,n} and (least gapsize)=2.at n=13A212895
- Irregular array T(n,k) of the numbers of non-extendable (complete) non-self-adjacent simple paths ending at each of a minimal subset of nodes within a square lattice bounded by rectangles with nodal dimensions n and 5, n >= 2.at n=47A214359
- Irregular array T(n,k) of the numbers of non-extendable (complete) non-self-adjacent simple paths ending at each of a minimal subset of nodes within a square lattice bounded by rectangles with nodal dimensions n and 8, n >= 2.at n=28A214375
- a(n) = Sum_{i=1...n} Sum_{j=1..i} lcm(i,j)/i.at n=38A232533
- Number of (n+1)X(2+1) 0..3 arrays with the maximum plus the minimum minus the upper median minus the lower median of every 2X2 subblock equal.at n=1A237294
- T(n,k)=Number of (n+1)X(k+1) 0..3 arrays with the maximum plus the minimum minus the upper median minus the lower median of every 2X2 subblock equal.at n=4A237299
- Number of partitions of n such that (least part) >= (multiplicity of least part).at n=39A240177
- Number of partitions p = [x(1), ..., x(k)], where x(1) >= x(2) >= ... >= x(k), of n such that max(x(i) - x(i-1)) is a part of p.at n=37A241735
- Numbers whose abundance is a power of 2.at n=35A259174