12255
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
- 2
Divisibility
- Divisor Count
- 16
- Divisor Sum
- 21120
- Proper Divisor Sum (Aliquot Sum)
- 8865
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 6048
- Möbius Function
- 1
- Radical
- 12255
- Omega Function (Ω)
- 4
- Little Omega Function (ω)
- 4
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
- 63
- 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_{j>=1} (1 - (-x)^j) - 1}^12 in powers of x.at n=12A001490
- Fibonacci sequence beginning 5, 17.at n=15A022141
- a(n) = n*(17*n - 1)/2.at n=38A022274
- Convolution of natural numbers with Beatty sequence for the golden mean A000201.at n=34A023541
- s(1)t(n) + s(2)t(n-1) + ... + s(k)t(n+1-k), where k = [ (n+1)/2 ], s = A023532, t = (Fibonacci numbers).at n=19A024367
- Sum_{ k=1 ... floor(n/2) } A023532(k)*Fib(n-k).at n=19A024371
- Erroneous version of A024371.at n=18A025067
- If d,e are consecutive digits of n in base 7, then |d-e|>=5.at n=33A032995
- If n is composite replace n with the concatenation of its nontrivial divisors [ A037279 ] then divide out any factors of 2.at n=19A037280
- Sums of 12 distinct powers of 2.at n=19A038463
- Base-7 palindromes that start with 5.at n=21A043019
- a(1) = 1 and for n > 1 let a(n) = a(n-1) + m, where m is the arithmetic mean of the largest subset of all predecessors such that m is an integer and m is maximal.at n=34A063676
- Numbers k such that the "inventory" A063850 of k is a perfect square.at n=12A079465
- Numbers k such that (k / sum of digits of k) and (k+1 / sum of digits of k+1) are both semiprime.at n=19A085774
- Total number of parts equal to 1 in all plane partitions of n.at n=13A090539
- Primitive elements of A119432.at n=25A119433
- Numbers k such that k and k^2 use only the digits 0, 1, 2, 5 and 8.at n=57A136825
- a(n) = (n-1)*(n+4)*(n+6)/6 for n > 1, a(1)=1.at n=38A137742
- Beginning of a run of 4 consecutive Niven (or Harshad) numbers.at n=13A141769
- Numbers k such that k, k + 1 and k + 2 are 3 consecutive Harshad numbers.at n=32A154701