6654
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 21
- Digital Root
- 3
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 13320
- Proper Divisor Sum (Aliquot Sum)
- 6666
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Highly Composite
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- yes
Derived Values
- Euler's Totient
- 2216
- Möbius Function
- -1
- Radical
- 6654
- 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
- 75
- 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
- yes
- Odd
- no
Appears in sequences
- Expansion of a modular function.at n=16A006707
- a(n) = s(1)t(n) + s(2)t(n-1) + ... + s(k)t(n-k+1), where k = [ n/2 ], s = (natural numbers), t = (composite numbers).at n=35A024860
- Numbers having three 1's in base 9.at n=36A043459
- T(n,n+3), array T as in A047140.at n=8A047148
- a(n) = a(n-1) + a(m) for n >= 3, where m = 2^(p+1) + 2 - n and p is the unique integer such that 2^p < n - 1 <= 2^(p+1), starting with a(1) = 1 and a(2) = 2.at n=44A050049
- Number of nonnegative integer 5 X 5 matrices with sum of elements equal to n, under row and column permutations.at n=9A052367
- Expansion of series related to Liouville's Last Theorem: g.f. Sum_{t>0} (-1)^(t+1) *x^(t*(t+1)/2) / ( (1-x^t)^3 *Product_{i=1..t} (1-x^i) ).at n=39A059820
- First occurrence of n as a term in the continued fraction for Pi/2.at n=52A076587
- Partial sums of A011764.at n=3A115245
- The first 10 digits of the fourth root of n contain the digits 0-9.at n=0A119519
- Numbers n such that first occurrence of the 10 digits of the i-th root of n contain all the digits from 0 to 9.at n=2A119521
- An antidiagonal triangular sequence based on sums of fractal self-similar level count totals of the sort: Sum_{n=0..m} k^(2^n).at n=13A130879
- Sum of all n-digit Woodall numbers.at n=3A131812
- Sums of 3 consecutive semiprimes.at n=28A173968
- Sums of three consecutive numbers each of which is the product of two distinct primes and each of which has no exponent greater than one for either of its two prime factors.at n=26A173969
- a(n) = 5*11^n - 1.at n=3A199022
- Number of nX2 0..3 arrays with rows and columns lexicographically nondecreasing and every element equal to at least one horizontal or vertical neighbor.at n=6A201619
- Number of nX7 0..3 arrays with rows and columns lexicographically nondecreasing and every element equal to at least one horizontal or vertical neighbor.at n=1A201624
- T(n,k)=Number of nXk 0..3 arrays with rows and columns lexicographically nondecreasing and every element equal to at least one horizontal or vertical neighbor.at n=29A201625
- T(n,k)=Number of nXk 0..3 arrays with rows and columns lexicographically nondecreasing and every element equal to at least one horizontal or vertical neighbor.at n=34A201625