10281
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 12
- Digital Root
- 3
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 14400
- Proper Divisor Sum (Aliquot Sum)
- 4119
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 6512
- Möbius Function
- -1
- Radical
- 10281
- 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
- yes
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 135
- 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
- a(n) = prime(n)*(prime(n-1)-1)/2.at n=32A014302
- Fibonacci sequence beginning 3, 15.at n=15A022381
- Numbers n such that n through n+5 have the same number of distinct prime factors.at n=14A045934
- a(n) = a(1) + a(2) + ... + a(n-1) - a(m) for n >= 4, where m = 2*n - 3 - 2^(p+1) and p is the unique integer such that 2^p < n - 1 <= 2^(p+1), starting with a(1) = 1 and a(2) = a(3) = 2.at n=15A049904
- A list of equal temperaments (equal divisions of the octave) whose nearest scale steps are closer and closer approximations to the ratios of two tones of musical harmony: the perfect 4th, 4/3 and its complement the perfect 5th, 3/2.at n=17A060528
- Numbers k such that sigma(k) and sigma(k+1) are nontrivial powers (A065496).at n=10A065522
- a(n) is the first of a triple of consecutive integers, each of which is the product of three distinct primes.at n=21A066509
- Numbers k such that phi((prime(k)-1)/2) = sigma(k).at n=34A068474
- Integers k such that nextprime(k^5) - prevprime(k^5) = 4.at n=7A090123
- a(n) = c is least number such that 10^n/2 -/+ c are primes.at n=35A124049
- Row sums of triangle A144285 (called S2hat(-4)).at n=4A144286
- a(n) = (prime(n))^2 - (nonprime(n))^2.at n=28A161757
- a(2*n+1) = 1+A131941(2*n+1). a(2*n) = A131941(2*n).at n=38A173809
- Triangle, read by rows, defined by T(n, k) = b(n) - b(k) - b(n-k) + 1 (see formula section for recurrence for b(n)).at n=46A176482
- Triangle, read by rows, defined by T(n, k) = b(n) - b(k) - b(n-k) + 1 (see formula section for recurrence for b(n)).at n=53A176482
- a(n) gives the number of nonisomorphic connected compact Lie groups of dimension n which are simple products.at n=50A177821
- Number of 0..n arrays x(0..7) of 8 elements with zero 5th differences.at n=19A200275
- Denominators of semiconvergents to log_2(3), which equals log(3)/log(2).at n=32A206788
- Composite numbers and 1 which yield a prime whenever a 1 is inserted anywhere in them, including at the beginning or end.at n=46A216165
- Number of n X 5 arrays of the minimum value of corresponding elements and their horizontal or diagonal neighbors in a random, but sorted with lexicographically nondecreasing rows and nonincreasing columns, 0..1 n X 5 array.at n=19A220029