6988
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 31
- Digital Root
- 4
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 6
- Divisor Sum
- 12236
- Proper Divisor Sum (Aliquot Sum)
- 5248
- 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
- 3492
- Möbius Function
- 0
- Radical
- 3494
- 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
- 150
- 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
- Powers of sqrt(5) rounded to nearest integer.at n=11A017920
- Powers of sqrt(5) rounded up.at n=11A017921
- Powers of fourth root of 5 rounded to nearest integer.at n=22A018058
- Powers of fourth root of 5 rounded up.at n=22A018059
- a(n) = T(n,1) + T(n-1,2) + ...+ T(n-k+1,k), where k = floor((n+1)/2) and T is the array defined in A026098.at n=32A026103
- Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 48 ones.at n=15A031816
- Nearest integer to n^(11/2).at n=5A036495
- Numbers k such that k-th and (k+1)-st term of A038593 differ by 5.at n=10A038636
- a(n) = smallest multiple of 4 with sum of digits = n.at n=30A077489
- Shifts 1 place left under the INVERT transform of the BINOMIAL transform of the self-convolution of this sequence.at n=6A090366
- Moebius transform of tetrahedral numbers.at n=35A117108
- G.f.: 1/p(x), where p(x) = degree 22 Salem polynomial p(x) = x^22 + x^21 - x^19 - 2*x^18 - 3*x^17 - 3*x^16 - 2*x^15 + 2*x^13 + 4*x^12 + 5*x^11 + 4*x^10 + 2*x^9 - 2*x^7 - 3*x^6 - 3*x^5 - 2*x^4 - x^3 + x + 1.at n=33A143419
- Number of numbers <= p^2 with largest prime factor <= p, where p is the n-th prime; a(0) = 1.at n=33A184677
- 1/3 the number of n X n 0..2 symmetric matrices with every element equal to zero or two horizontal and vertical neighbors.at n=4A211037
- a(n) is the sum of all distinct integers that can be produced by reversing the digits of n in any base b >= 2.at n=40A211518
- Number of (w,x,y) with all terms in {0,...,n} and the numbers w,x,y,|w-x|,|x-y| not distinct.at n=27A213491
- Number of 4 X n 0..2 arrays with horizontal differences mod 3 never 1, vertical differences mod 3 never -1, and rows and columns lexicographically nondecreasing.at n=12A229447
- 7-step Fibonacci sequence starting with (0,0,1,0,0,0,0).at n=20A251713
- The smallest amount which cannot be made with fewer than n British coins.at n=40A258272
- G.f.: Product_{k>=1} (1+x^(k^2)) / (1-x^k).at n=26A280204