2645
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 17
- Digital Root
- 8
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 6
- Divisor Sum
- 3318
- Proper Divisor Sum (Aliquot Sum)
- 673
- 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
- 2024
- Möbius Function
- 0
- Radical
- 115
- 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
- 115
- 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
- Numbers m such that Fibonacci(m) ends with m.at n=48A000350
- Related to S(n), the number of self-dual monotone Boolean functions of n variables (A001206): 2^n-th term is S(n).at n=30A001087
- Number of partitions of n into parts 1/2, 3/4, 7/8, 15/16, etc.at n=14A002843
- a(n) = prime(n) + Fibonacci(n).at n=17A004397
- Coordination sequence T3 for Zeolite Code AFR.at n=39A008021
- Number of immersions of the unoriented circle into the unoriented plane with n double points.at n=6A008983
- Coordination sequence T2 for Zeolite Code RUT.at n=34A009898
- Concentric pentagonal numbers: floor( 5*n^2 / 4 ).at n=46A032527
- a(n) = 5*n^2.at n=23A033429
- Convolution of natural numbers n >= 1 with Fibonacci numbers F(k), for k >= -5, with F(-n)=(-1)^(n+1)*F(n);.at n=19A037141
- Coordination sequence T5 for Zeolite Code STT.at n=34A038415
- Numbers whose base-2 representation has exactly 11 runs.at n=2A043578
- a(n) = (1/2)*(n-th number whose base-2 representation has exactly 12 runs).at n=2A043686
- a(n) = (s(n)-1)/2, where s(n) is the n-th number whose base-2 representation has exactly 11 runs.at n=26A043691
- Numbers n such that number of runs in the base 2 representation of n is congruent to 1 mod 10.at n=13A043764
- Numbers n such that string 5,8 occurs in the base 9 representation of n but not of n-1.at n=35A044304
- Numbers n such that string 4,5 occurs in the base 10 representation of n but not of n-1.at n=29A044377
- Numbers n such that string 5,5 occurs in the base 9 representation of n but not of n+1.at n=32A044682
- Numbers n such that string 5,8 occurs in the base 9 representation of n but not of n+1.at n=35A044685
- Numbers n such that string 4,5 occurs in the base 10 representation of n but not of n+1.at n=29A044758