2605
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 13
- Digital Root
- 4
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 3132
- Proper Divisor Sum (Aliquot Sum)
- 527
- 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
- 2080
- Möbius Function
- 1
- Radical
- 2605
- 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
- 102
- Smith Number
- yes
- 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
- Number of partitions of n into prime parts.at n=63A000607
- Narayana-Zidek-Capell numbers: a(n) = 1 for n <= 2. Otherwise a(2n) = 2a(2n-1), a(2n+1) = 2a(2n) - a(n).at n=14A002083
- a(n) = floor(n*phi^13), where phi is the golden ratio, A001622.at n=5A004928
- a(n) = round(n*phi^13), where phi is the golden ratio, A001622.at n=5A004948
- a(n) = 1 + n/2 + 9*n^2/2.at n=24A006137
- Number of sensed 2-connected (nonseparable) planar maps with n edges.at n=8A006402
- Coordination sequence T1 for Zeolite Code DDR.at n=32A008071
- Coordination sequence T1 for Zeolite Code YUG.at n=33A008247
- Coordination sequence T2 for Zeolite Code CON.at n=36A009869
- Least d for which the number with continued fraction [n,n,n,n...] is in Q(sqrt(d)).at n=50A013946
- Expansion of x/(1 - 6*x - 11*x^2).at n=5A015553
- a(n) = b(n) + d(n), where b(n) = (n-th Fibonacci number > 2) and d(n) = (n-th non-Lucas number).at n=14A023494
- a(n) = b(n) + d(n), where b(n) = ( (n+1)st Fibonacci number) and d(n) = (n-th number that is 1, 2, or 3, or is not a Lucas number).at n=16A023499
- Golc sequence in base 2. Left to right concatenation of n,int(log_2(n)),int(log_2(int(log_2(n)))),... in base 2.at n=39A028432
- Odd composite numbers n such that the digit sum of n equals digit sum of sum of its prime factors (counted with multiplicity).at n=35A036923
- Digit sum of 'odd' number equals digit sum of 'sum' and 'juxtaposition' of its prime factors (counted with multiplicity).at n=21A036927
- Positive numbers having the same set of digits in base 5 and base 7.at n=35A037430
- Coordination sequence T3 for Zeolite Code AWO.at n=35A038405
- Coordination sequence T1 for Zeolite Code SFF.at n=34A038437
- Numerators of continued fraction convergents to sqrt(192).at n=4A041356