6939
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 27
- Digital Root
- 9
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 10320
- Proper Divisor Sum (Aliquot Sum)
- 3381
- 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
- 4608
- Möbius Function
- 0
- Radical
- 771
- Omega Function (Ω)
- 4
- 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
- yes
- Narcissistic Number
- no
- Collatz Steps
- 88
- 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
- no
- Odd
- yes
Appears in sequences
- a(n) = n*(19*n + 1)/2.at n=27A022277
- 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 83.at n=4A031581
- Numbers n such that 137 * 2^n + 1 is a prime.at n=9A032418
- Numbers k such that 227*2^k+1 is prime.at n=10A032490
- Number of days in n years (n=4 is the first leap year).at n=18A033171
- a(1) = 3; a(n) is smallest number >= a(n-1) such that the juxtaposition a(1)a(2)...a(n) is a prime.at n=39A033681
- Base-4 digits are, in order, the first n terms of the periodic sequence with initial period 1,2,3,0.at n=6A037695
- Family 1 "Rule 90 x Rule 150 Array" read by antidiagonals.at n=22A048710
- 2nd row of Family 1 "90 X 150 array": generations 0 .. n of Rule 90 starting from seed pattern 7.at n=5A048711
- An auxiliary bit-mask sequence for computing A066425. (The "clean", symmetric one).at n=3A068221
- Numbers k such that gcd(k, reverse(k)) = 27 = 3^3, where reverse(x) = A004086(x).at n=16A072016
- a(1) = 2; a(n) is smallest number > a(n-1) such that the juxtaposition a(1)a(2)...a(n) is a prime.at n=47A074338
- Number of ways to partition the sum of all divisors of n (sigma(n), A000203) into distinct positive integers not greater than n.at n=38A079125
- Sum of the n smallest numbers having the sum of their digits equal to n.at n=17A081928
- Integer part of the area of circles with prime radii.at n=14A097427
- a(n) = 3*(2*n^2 + 1).at n=34A097803
- Expansion of (1 - 3*x - sqrt((1-3*x)^2 - 4*3*x^2))/(2*3*x^2).at n=6A107264
- A square array of Motzkin related transforms, read by antidiagonals.at n=48A107267
- Numbers n such that googol - n is prime.at n=23A108251
- a(1) = 1; for n>1, a(n) = least k such that concatenation of n copies of k with all previous concatenations gives a prime.at n=28A111471