16875
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 27
- Digital Root
- 9
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 20
- Divisor Sum
- 31240
- Proper Divisor Sum (Aliquot Sum)
- 14365
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 9000
- Möbius Function
- 0
- Radical
- 15
- Omega Function (Ω)
- 7
- 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
- 58
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- no
- Squarefree Number
- no
- Prime Power
- no
- Prime Factorization
- no
- Twin Prime
- no
- Mersenne Prime
- no
- Sophie Germain Prime
- no
- Safe Prime
- no
- Powerful Number
- yes
- Achilles Number
- yes
- Perfect Power
- no
- Smooth Number
- yes
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Numbers of the form 3^i*5^j with i, j >= 0.at n=34A003593
- Sorted k-factorial numbers (numbers of form k-1 excluded).at n=31A028687
- Sorted factorial and k-factorial numbers (numbers of form k-1 excluded).at n=37A028688
- Numbers whose prime factors are 3 and 5.at n=19A033849
- a(1)=8; if n = Product p_i^e_i, n > 1, then a(n) = Product p_{i+1}^{e_i+2}.at n=17A045971
- Odd numbers divisible by exactly 7 primes (counted with multiplicity).at n=15A046320
- Digitally balanced numbers in base 4: equal numbers of 0's, 1's, ... 3's.at n=21A049355
- Values of e, the lesser key or generating number for Pythagorean triangles in which S (the odd short leg) and U (the hypotenuse) are twin primes.at n=39A051892
- Number of points in Z^5 of norm <= n.at n=5A055411
- Number of points in Z^n of norm <= 5.at n=5A055429
- Numbers k such that k | 5^k + 4^k + 3^k + 2^k + 1^k.at n=41A056741
- Numbers n such that n | 9^n + 8^n + 7^n + 6^n + 5^n + 4^n + 3^n + 2^n + 1^n.at n=43A056754
- Numbers n such that n | 6^n + 5^n + 4^n.at n=43A057235
- Numbers n such that n | 11^n + 10^n + 9^n + 8^n + 7^n.at n=46A057251
- Numbers k such that S(k)=d(k), where S(k) is the Kempner function (A002034) and d(k) is the number of divisors of k (A000005).at n=17A073307
- Numbers n such that number of divisors of n divides S(n), the Kempner function A002034.at n=28A073413
- Expansion of (1-x)^(-1)/(1+2*x+2*x^2-2*x^3).at n=16A077932
- Coefficient triangle for computation of column numbers of triangle A071951 (Legendre-Stirling).at n=14A089278
- Expansion of g.f. (1-10x)/(1-15x).at n=4A091882
- a(n) divides the number formed by concatenating the sum of the digits of a(n) with a(n), by a factor not previously used.at n=11A101171