8723
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
- 4
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 10416
- Proper Divisor Sum (Aliquot Sum)
- 1693
- 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
- 7200
- Möbius Function
- -1
- Radical
- 8723
- Omega Function (Ω)
- 3
- 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
- 140
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- no
- 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
- a(n) = A026615(2*n-1, n-2).at n=6A026620
- a(n) = T(2n,n+2), T given by A026736.at n=6A026851
- The sequence e when b=[ 1,1,0,1,1,... ].at n=47A042955
- Numbers whose base-5 representation contains exactly three 3's and two 4's.at n=24A045306
- Dana Scott's sequence: a(n) = (a(n-2) + a(n-1) * a(n-3)) / a(n-4), a(0) = a(1) = a(2) = a(3) = 1.at n=16A048736
- (Terms in A028279)/2.at n=61A051358
- (Terms in A028286)/2.at n=24A051359
- a(n) = n * (6*n^2 + 6*n + 1).at n=10A094421
- Look at the first 10 digits of the sequence: they are all different. The same for the next 10. And the next 10, etc. This sequence is the slowest increasing one with that property.at n=46A097912
- Numbers k such that k + prime(k) gives a triangular number.at n=34A115882
- A106486-encodings of combinatorial games equivalent to game {0|0}.at n=22A125994
- Expansion of 1/(x^k*(1-x-2*x^(k+1))) for k=8.at n=33A143451
- 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, 0), (-1, 1, -1), (-1, 1, 1), (0, 0, 1), (1, 0, 0)}.at n=8A149939
- Number of natural numbers between exponents of successive Mersenne primes.at n=22A157891
- a(n) = Sum_{k<=n} A000203(k)*(n-k+1), where A000203(m) is the sum of divisors of m.at n=30A175254
- Third accumulation array, T, of the natural number array A000027, by antidiagonals.at n=64A185508
- Power ceiling-floor sequence of sqrt(5).at n=10A218982
- Number of decompositions of highly composite numbers (A002182) into unordered sums of two primes.at n=35A228943
- Number of sequences of 5 throws of an n-sided die (with faces numbered 1, 2, ..., n) in which the sum of the throws first reaches or exceeds n on the 5th throw.at n=9A264750
- Sum of the site-perimeters of all bargraphs of area n.at n=10A274217