5505
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 15
- Digital Root
- 6
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 8832
- Proper Divisor Sum (Aliquot Sum)
- 3327
- 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
- 2928
- Möbius Function
- -1
- Radical
- 5505
- 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
- yes
- Narcissistic Number
- no
- Collatz Steps
- 191
- 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
- Expansion of Product_{m>=1} (1+q^m)^(-6).at n=14A022601
- Least m such that if r and s in {1/2, 1/5, 1/8,..., 1/(3n-1)}, satisfy r < s, then r < k/m < s for some integer k.at n=48A024823
- a(n) = (1/4 + 1/6 + ... + 1/c(n))*LCM{4, 6, ..., c(n)}, where c(n) = n-th composite number.at n=9A025545
- An "extremely strange sequence": a(n+1) = [ A*a(n)+B ]/p^r, where p^r is the highest power of p dividing [ A*a(n)+B ] and p=2, A=4.001, B=1.2.at n=34A028948
- Numbers having three 5's in base 10.at n=10A043511
- a(n) = a(n-1) + a(m) for n >= 4, where m = 2^(p+1) + 2 - n and p is the unique integer such that 2^p < n - 1 <= 2^(p+1), starting with a(1) = a(2) = 1 and a(3) = 3.at n=44A050033
- Odd numbers seen in decimal expansion of Pi (disregarding the decimal period) contiguous, smallest and distinct.at n=35A050817
- Second spoke of a hexagonal spiral.at n=43A056106
- McKay-Thompson series of class 8b for Monster.at n=28A058088
- Numbers k such that k and its reversal are both multiples of 15.at n=40A062905
- Non-palindromic number and its reversal are both multiples of 15.at n=34A062914
- Number of ways of making change for n cents using coins of sizes 1, 2, 5, 10 cents, when order matters.at n=17A073031
- Partial sums of usigma(n)^2: square of the sum of unitary divisors of n.at n=19A074789
- Interprimes which are of the form s*prime, s=15.at n=27A075290
- 2-apexes of omega: numbers k such that omega(k-2) < omega(k-1) < omega(k) > omega(k+1) > omega(k+2), where omega(m) = the number of distinct prime factors of m.at n=26A076762
- Positive integers k such that k!!! - 1 = A007661(k) - 1 is prime.at n=17A084438
- Numbers k such that k + (largest digit of k)! is a square.at n=35A095927
- McKay-Thompson series of class 8c for the Monster group.at n=28A112145
- McKay-Thompson series of class 16a for the Monster group.at n=14A112150
- Number of (ordered) sequences of coins (each of which has value 1, 2, 5, 10, 20, 50, 100 or 200) which add to n.at n=17A114138