6626
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
- 3
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 9942
- Proper Divisor Sum (Aliquot Sum)
- 3316
- 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
- 3312
- Möbius Function
- 1
- Radical
- 6626
- 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
- 93
- 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
- yes
- Odd
- no
Appears in sequences
- A nonlinear binomial sum.at n=15A000128
- Number of points on surface of truncated cube: a(n) = 46*n^2 + 2 for n > 0.at n=12A005911
- a(n) = (5*n + 1)^2 + 4*n + 1.at n=16A007533
- Numbers k such that the continued fraction for sqrt(k) has period 3.at n=22A013643
- Sum of reciprocals of digits = 1.at n=38A037268
- Numerators of continued fraction convergents to sqrt(795).at n=3A042532
- Numbers having three 6's in base 10.at n=14A043515
- Let (u1,u2) be successive untouchable numbers such that phi(u1) = phi(u2); sequence gives values of u1.at n=20A048189
- Number of unlabeled 5-gonal cacti having n polygons.at n=7A054365
- Harmonic mean of digits is 4.at n=40A062182
- Numbers m such that [A070080(m), A070081(m), A070082(m)] is an acute scalene integer triangle with prime side lengths.at n=15A070123
- Trajectory of n under the Reverse and Add! operation carried out in base 3 (presumably) does not reach a palindrome and (presumably) does not join the trajectory of any term m < n.at n=15A077405
- Decimal concatenations of the quadruples (d1,d2,d3,d4) with elements in {2,4,6} for which there exists a prime p >= 5 such that the differences between the 5 consecutive primes starting with p are (d1,d2,d3,d4).at n=21A078868
- a(n) = 3*n^2 - 1.at n=46A080663
- a(n) is the smallest number x such that gcd(prime(x)+1,x+1) = n.at n=46A084316
- G.f. A(x) satisfies both A(-x)*A(x) = A(x^2) and xA(x)^2 = B(xA(x^2)) where B(x) = x*(1+x)/(1-x).at n=21A091188
- Number of one-element transitions among partitions of the integer n for labeled parts.at n=15A094533
- a(n) = 4 + 8*n + 10*n^2 + 4*n^3.at n=11A100207
- Near-repdigit semiprimes with 6 as repeated digit.at n=12A105987
- The (1,1)-entry of the matrix M^n, where M is the 5 X 5 matrix [[0,1,0,0,0],[0,0,1,0,0], [0,0,0,1,0], [0,0,0,0,1], [1,0,-1,1,1]].at n=29A107293