8727
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 24
- Digital Root
- 6
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 4
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 11640
- Proper Divisor Sum (Aliquot Sum)
- 2913
- 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
- 5816
- Möbius Function
- 1
- Radical
- 8727
- Omega Function (Ω)
- 2
- 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
- 140
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- yes
- 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
- Numbers k such that the continued fraction for sqrt(k) has even period and if the last term of the periodic part is deleted the central term is 31.at n=30A031529
- Number of ways to place zero or more nonadjacent 1,0 1,1 2,0 3,0 4,1 5,2 polyhexes in any orientation on a planar nXnXn triangular grid.at n=6A155298
- Partial sums of A213709.at n=16A218600
- Numbers n such that 6n -/+ 1 are twin prime pair and n = r + s where 6r -/+ 1 and 6s -/ 1 are consecutive smaller pairs of twin primes.at n=52A226652
- The number of tilings of a triangular shape T_n with n rectangles identifying all tilings which use the same rectangular shapes.at n=14A247139
- Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 201", based on the 5-celled von Neumann neighborhood.at n=24A270722
- Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 838", based on the 5-celled von Neumann neighborhood.at n=34A273681
- Number x = concat(MSD(x),b) such that MSD(x)*b = phi(x), where MSD(x) is the Most Significant Digit of x and phi(x) is the Euler totient function of x.at n=20A286130
- Number of nX3 0..1 arrays with every element equal to 1, 2, 4, 5, 6 or 8 king-move adjacent elements, with upper left element zero.at n=9A299509
- Number of locally disjoint rooted identity trees with n nodes, meaning no branch overlaps any other branch of the same root.at n=15A316471
- a(0) = a(1) = a(2) = 1; thereafter a(n) = a(n-1) - (-1)^n*a(n-2) + 2*a(n-3).at n=31A329301
- Numbers of the form ab such that phi(ab) = a*b where ab is the concatenation of a and b.at n=39A336237
- Numbers of the form ab such that uphi(ab) = a*b where ab is the concatenation of a and b.at n=18A337523
- G.f. A(x) satisfies: 1 = Sum_{n=-oo..+oo} (x^n - 2*x*A(x))^n.at n=10A355868
- Triangle read by rows. Convolution triangle of the Bell numbers.at n=60A357583
- Central terms of the convolution triangle of the Bell numbers (A357583).at n=5A357584
- Semiprimes that are the sum of two successive terms of A092192.at n=39A366167
- Table in which the g.f. of row n, R(n,x), satisfies Sum_{k=-oo..+oo} (x^k - n*R(n,x))^k = 1 - (n-2)*Sum_{k>=1} x^(k^2), for n >= 1, as read by antidiagonals.at n=76A370030