17647
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 25
- Digital Root
- 7
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 20176
- Proper Divisor Sum (Aliquot Sum)
- 2529
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 15120
- Möbius Function
- 1
- Radical
- 17647
- 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
- 278
- 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
- In the '3x+1' problem, these values for the starting value set new records for number of steps to reach 1.at n=28A006877
- In the '3x+1' problem, these values for the starting value set new records for number of steps to reach 1.at n=22A033958
- Base 7 digits are, in order, the first n terms of the periodic sequence with initial period 1,0,2,3.at n=5A037677
- a(n) = 10*n^2 + 7.at n=42A061722
- n sets a record for the number of primes in {n, f(n), f(f(n)), ..., 1}, where f is the Collatz function defined by f(x) = x/2 if x is even; f(x) = 3x + 1 if x is odd.at n=14A078373
- a(n) = 15*n^2 + 9*n + 1.at n=34A134153
- The smallest positive integer that produces exactly n primes in a Collatz trajectory.at n=47A181921
- 50k^2-20k-23 interleaved with 50k^2+30k+17 for k=>0.at n=38A217894
- Total sum of parts of multiplicity 4 in all partitions of n.at n=35A222732
- Let m = n-th number not divisible by 3 (A001651); a(n) = position of m in A065075, or -1 if never appears in A065075.at n=27A230289
- Number of permutations f of {1,...,n} such that 3^k + 3^(f(k)) - 1 is prime for every k = 1,...,n.at n=21A321766
- Number of permutations f of {1,...,n} such that 3^k + 3^(f(k)) - 1 is prime for every k = 1,...,n.at n=22A321766
- Number of permutations f of {1,...,n} such that 3^k + 3^(f(k)) - 1 is prime for every k = 1,...,n.at n=24A321766
- Composite numbers k such that A006577(k) sets a new record.at n=23A346591