17845
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
- 2
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 22176
- Proper Divisor Sum (Aliquot Sum)
- 4331
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 13776
- Möbius Function
- -1
- Radical
- 17845
- Omega Function (Ω)
- 3
- Little Omega Function (ω)
- 3
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
- 97
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- no
- 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
- Spiral sieve using Fibonacci numbers.at n=20A005620
- Number of partitions satisfying cn(0,5) <= cn(1,5) + cn(4,5) + cn(2,5) + cn(3,5).at n=35A039849
- Average of four successive primes squared, (prime(n)^2 + prime(n+1)^2 + prime(n+2)^2 + prime(n+3)^2)/4, n>=2.at n=29A075894
- Convolution of odd primes with themselves.at n=20A084370
- First integer > n reached under iteration of map x -> (5/3)*ceiling(x) when started at n, or -1 if no such integer is ever reached.at n=37A087708
- a(n) = least k such that the remainder when 16^k is divided by k is n.at n=40A128156
- Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, -1, 0), (-1, 0, -1), (-1, 0, 0), (-1, 1, 1), (1, 0, 0)}.at n=10A148530
- a(n) = binary code (shown here in decimal) of the position of natural number n in the beanstalk-tree A218778.at n=35A218614
- Composite numbers k such that if k = a U b (where U denotes concatenation) then a' + b' = k', where a', b' and k' are the arithmetic derivatives of a, b and k.at n=10A239724
- Composite numbers k = concat(MSD(k),x) such that k' = x', where k' is the arithmetic derivative of k.at n=7A293477
- Number of distinct sorted degree sequences among all n-vertex loop-graphs without isolated vertices.at n=9A339845