7580
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
- 1
Divisibility
- Divisor Count
- 12
- Divisor Sum
- 15960
- Proper Divisor Sum (Aliquot Sum)
- 8380
- 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
- 3024
- Möbius Function
- 0
- Radical
- 3790
- Omega Function (Ω)
- 4
- 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
- 176
- 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
- Dedekind numbers: monotone Boolean functions, or nonempty antichains of subsets of an n-set.at n=5A014466
- a(n) = dot_product(1,2,...,n)*(6,7,...,n,1,2,3,4,5).at n=24A026046
- "DHK" (bracelet, identity, unlabeled) transform of 1,3,5,7,...at n=11A032255
- a(n) = a(1) + a(2) + ... + a(n-1) - a(m) for n >= 4, where m = 2*n - 2 - 2^(p+1) and p is the unique integer such that 2^p < n - 1 <= 2^(p+1), starting with a(1) = 1, a(2) = 2 and a(3) = 4.at n=15A049915
- Numbers k such that 80*R_k + 7 is prime, where R_k = 11...1 is the repunit (A002275) of length k.at n=16A056695
- Numbers k such that (k+1)*phi(k) is a perfect square.at n=15A069952
- Interprimes which are of the form s*prime, s=20.at n=11A075295
- Scaled array A078740 ((3,2)-Stirling2).at n=31A090452
- Numbers m such that f(k) * 2^m - 1 is prime, where f(j) = A070826(j) and k is the number of decimal digits of 2^m.at n=32A095991
- Number of antichains in the first n elements of the infinite Boolean lattice.at n=31A132581
- First differences of A132581.at n=32A132582
- Partial sums of A051941.at n=14A136105
- 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), (-1, 0, 1), (0, 1, 1), (1, 0, 0), (1, 1, -1)}.at n=7A150285
- a(n) = n^3 - n^2 - n.at n=20A152015
- a(n) = 361*n - 1.at n=20A158308
- Array A(k,n) of the number of points of the A_k lattice with maximum infinity norm n, read by antidiagonals.at n=39A175197
- Partial sums of sequence A177342.at n=11A178073
- Number of (n+2)X3 0..1 arrays with every 3X3 subblock having three equal elements in a row horizontally, vertically, diagonally or antidiagonally exactly one way, and new values 0..1 introduced in row major order.at n=4A204354
- Number of (n+2)X7 0..1 arrays with every 3X3 subblock having three equal elements in a row horizontally, vertically, diagonally or antidiagonally exactly one way, and new values 0..1 introduced in row major order.at n=0A204358
- T(n,k)=Number of (n+2)X(k+2) 0..1 arrays with every 3X3 subblock having three equal elements in a row horizontally, vertically, diagonally or antidiagonally exactly one way, and new values 0..1 introduced in row major order.at n=10A204361