16530
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 15
- Digital Root
- 6
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 32
- Divisor Sum
- 43200
- Proper Divisor Sum (Aliquot Sum)
- 26670
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 4032
- Möbius Function
- -1
- Radical
- 16530
- Omega Function (Ω)
- 5
- Little Omega Function (ω)
- 5
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
- 141
- 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
- yes
- Odd
- no
Appears in sequences
- Numbers n such that sum of distinct primes dividing n is divisible by the largest prime dividing n. Also n is neither a prime, nor a true power of prime and n is squarefree. Squarefree solutions of A071140.at n=18A071141
- Numbers n such that sum of distinct primes dividing n is divisible by the largest prime dividing n. Also n has exactly 5 distinct prime factors and n is squarefree.at n=4A071144
- Squarefree numbers k such that the largest prime factor of k is equal to the sum of the other prime factors of k.at n=17A071312
- Sum of terms of n-th group in A075383.at n=28A075386
- Records in A118878.at n=11A119903
- Composite numbers that are products of distinct primes and divisible by the sum of those primes.at n=39A131647
- Composites one larger than a prime, with exactly five distinct prime factors.at n=34A136154
- Numbers k such that k*(k+1)-1 and k*(k+1)+1 are twin primes and k*(k+3)-1 and k*(k+3)+1 are also twin primes.at n=14A138303
- Ten times hexagonal numbers: 10*n*(2*n-1).at n=29A144560
- a(n) = 19*n*(n+1).at n=29A173309
- a(n) = product{ p primes <= n+1 such that p divides n+1 or p-1 divides n }.at n=56A225481
- Alternating sum of hexagonal pyramidal numbers.at n=36A266677
- a(n) is the smallest m such that A001414(m)=n and ((m=0) mod n) and m/n is both squarefree and prime to n, or 0 if no such m exists.at n=56A267000
- a(n) = (2*n+1)*denominator((2*n+1)*Bernoulli(2*n)).at n=28A326580
- Expansion of e.g.f. (exp(x)-1)^2*(x+x^2/2).at n=10A360588
- Numbers k such that omega(k) = 5 and the largest prime factor of k equals the sum of its remaining distinct prime factors, where omega(k) = A001221(k).at n=6A383729
- Squarefree numbers whose distinct prime factors can be partitioned into two sets with equal sums.at n=41A384498