8564
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 23
- Digital Root
- 5
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 6
- Divisor Sum
- 14994
- Proper Divisor Sum (Aliquot Sum)
- 6430
- 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
- 4280
- Möbius Function
- 0
- Radical
- 4282
- Omega Function (Ω)
- 3
- 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
- 26
- 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
- Number of partitions into non-integral powers.at n=15A000263
- Numbers k such that the continued fraction for sqrt(k) has period 70.at n=31A020409
- Expansion of tan(x)*tan(sinh(x))/2.at n=4A024292
- a(n) = (d(n)-r(n))/2, where d = A026063 and r is the periodic sequence with fundamental period (1,1,0,1).at n=36A026064
- Number of 1-connected rooted cubic planar maps with n faces.at n=5A058859
- Sum of first n perfect powers.at n=35A076408
- Numbers n such that (sigma(n-2)+sigma(n+2))/2 = sigma(n).at n=26A099631
- Concatenation of first two digits and last two digits of n-th even superperfect number A061652(n).at n=11A138869
- Number of 5 X n 0..1 arrays with diagonals and antidiagonals unimodal and rows nondecreasing.at n=7A223952
- Number of nX4 0..3 arrays with no element equal to the sum of elements to its left or the sum of elements above it or the sum of the elements diagonally to its northwest or the sum of the elements antidiagonally to its northeast, modulo 4.at n=5A240246
- T(n,k)=Number of nXk 0..3 arrays with no element equal to the sum of elements to its left or the sum of the elements above it or the sum of the elements diagonally to its northwest or the sum of the elements antidiagonally to its northeast, modulo 4.at n=41A240250
- Number of 6Xn 0..3 arrays with no element equal to the sum of elements to its left or the sum of the elements above it or the sum of the elements diagonally to its northwest or the sum of the elements antidiagonally to its northeast, modulo 4.at n=3A240255
- Number of partitions of n into parts > 0 without 1 as digit, cf. A052383.at n=51A248518
- Numbers n such that the decimal number concat(5,n) is a square.at n=24A273360
- Solution of the complementary equation a(n) = 2*a(n-1) - a(n-2) + b(n-1) -1, where a(0) = 1, a(1) = 2, b(0) = 3, and (a(n)) and (b(n)) are increasing complementary sequences.at n=34A294867
- G.f. A(x) satisfies: [x^(n-1)] (1 + x*A(x)^(n-1))^n / A(x)^n = 0 for n>1.at n=6A303062
- a(n) is the surface area of the stepped pyramid with n levels described in A245092.at n=47A328366
- Number of inversion sequences of length n avoiding the consecutive patterns 000 and 001.at n=8A328436
- Numbers k such that sigma(k) == 2 modulo 8 and sigma(sigma(k)) == 6 modulo 8.at n=48A332457
- Smallest even fundamental discriminant k such that h(-k) = 2n, where h(D) is the class number of the quadratic field with discriminant D; or 0 if no such k exists.at n=38A344072