12655
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 19
- Digital Root
- 1
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 15192
- Proper Divisor Sum (Aliquot Sum)
- 2537
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 10120
- Möbius Function
- 1
- Radical
- 12655
- 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
- yes
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 55
- 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
- Number of n-dimensional partitions of 5.at n=19A008779
- Smallest k>1 such that k(p-1)-1 is divisible by p^2, p=n-th prime.at n=29A039914
- Denominators of convergents to the diesis log_2(5/4).at n=8A046104
- A list of equal temperaments (equal divisions of the octave) whose nearest scale steps are closer and closer approximations to the pair of ratios 5/4 and 8/5 which generate two complementary tones of musical harmony, the Major 3rd (5/4) and the Minor 6th (8/5).at n=18A061918
- a(1) = 1, a(n+1) is the sum of a(n) and floor( arithmetic mean of a(1) ... a(n) ).at n=38A065094
- Centered 18-gonal numbers.at n=37A069131
- Centered 19-gonal numbers.at n=36A069132
- Sum of GCD's of parts in all partitions of n.at n=33A078392
- Number of partitions of n into nonsquares.at n=52A087153
- One seventh of the sum of the first n primes, when an integer.at n=25A112272
- Denominators of the convergents to the continued fraction for log_2(5)/4.at n=13A112732
- Duplicate of A046104.at n=8A116984
- Numbers of the form k^2 - k - 1 whose digit sum is also a number of the form k^2 - k - 1.at n=40A117746
- Numbers k such that the k-th triangular number contains only digits {0,4,8}.at n=0A119076
- p^2-p-1 that is not prime, where p is prime.at n=16A119609
- a(n) = (n^3 + 18*n^2 + 17*n + 6)/6.at n=37A143058
- Number of third differences of arrays of length 5 of numbers in 0..n.at n=18A228261
- Floor of the solutions to c = exp(1 + n/c) for n >= 0, using recursion.at n=23A234604
- Number of sets of exactly n positive integers <= n+8 having a square element sum.at n=14A281971
- a(n) = p^2 - p - 1 where p = prime(n), the n-th prime.at n=29A306190