2559
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
- 4
- Divisor Sum
- 3416
- Proper Divisor Sum (Aliquot Sum)
- 857
- 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
- 1704
- Möbius Function
- 1
- Radical
- 2559
- 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
- 115
- 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
- no
- Odd
- yes
Appears in sequences
- G.f. is 1 - 1/f(x), where f(x) = 1+x+3*x^2+9*x^3+32*x^4+... is 1/x times g.f. for A063020.at n=7A007858
- Coordination sequence T2 for Zeolite Code MAZ.at n=35A008145
- Coordination sequence T7 for Zeolite Code PAU.at n=37A008225
- Coordination sequence T4 for Zeolite Code -PAR.at n=36A009858
- a(n) = 2*a(n-2) + 1.at n=18A010737
- Numbers k such that the continued fraction for sqrt(k) has period 34.at n=22A020373
- Numbers k such that Fibonacci(k) == -2 (mod k).at n=40A023163
- Convolution of Lucas numbers and primes.at n=10A023625
- a(n) = (1/s(1) + 1/s(2) + ... + 1/s(n+1)) * LCM{1, 2, ..., n}, where s(k) = LCM{1,2,...,k}/k = A002944(k).at n=8A025537
- a(n) = n^2 + n + 9.at n=50A027694
- Numbers whose base-4 representation has 4 fewer 0's than 3's.at n=21A031469
- 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 32.at n=24A031530
- Number of odd nonprimes < (2n+1)^2.at n=41A037040
- Molien series for 3-D group R4.at n=12A037243
- Sums of 10 distinct powers of 2.at n=11A038461
- Numbers having four 3's in base 4.at n=31A043348
- Numbers having three 7's in base 8.at n=4A043451
- Numbers k such that the string 5,3 occurs in the base 9 representation of k but not of k-1.at n=34A044299
- Numbers n such that string 5,9 occurs in the base 10 representation of n but not of n-1.at n=27A044391
- Numbers n such that string 7,7 occurs in the base 8 representation of n but not of n+1.at n=39A044631