17887
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 31
- Digital Root
- 4
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 4
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 18496
- Proper Divisor Sum (Aliquot Sum)
- 609
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 17280
- Möbius Function
- 1
- Radical
- 17887
- 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
- yes
- Narcissistic Number
- no
- Collatz Steps
- 154
- 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
- a(n) = a(n-1) + a(n-6), with a(i) = 1 for i = 0..5.at n=42A005708
- Expansion of 1/(1 - x^6 - x^7 - x^8 - ...).at n=48A017900
- Number of 4 X n binary matrices such that any 2 rows have a common 1.at n=4A051587
- a(1) = a(2) = 1. For n >=3, a(n) = the a(n-2)th integer, among those positive integers which are missing from the first (m-1) terms of the sequence, below a(n-1) if such a positive integer exists. Otherwise, a(n) = the a(n-2)th integer, among those positive integers which are missing from the first (m-1) terms of the sequence, above a(n-1).at n=35A118627
- Squarefree k > 1 with sigma(sigma(sigma(k))) < 3*k + 1.at n=24A320513
- Number of finite sets of integer partitions with all equal sums and total sum n.at n=35A359041
- Number of integer partitions of n whose multiset of multiplicities has integer mean.at n=45A360069
- Number of compositions of 6*n into parts 1 and 6.at n=7A371125
- a(n) = Sum_{k=0..floor(n/2)} binomial(3*n-5*k,k).at n=14A373638
- a(n) = Sum_{k=0..floor(n/3)} binomial(2*n-5*k,k).at n=21A373639
- Number of rooted full binary trees with n internal nodes, up to their multiset of subtree sizes.at n=15A382440