12279
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 21
- Digital Root
- 3
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 16376
- Proper Divisor Sum (Aliquot Sum)
- 4097
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 8184
- Möbius Function
- 1
- Radical
- 12279
- 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
- 125
- 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
- Sums of 12 distinct powers of 2.at n=21A038463
- Number of partitions satisfying 0 < cn(0,5) + cn(1,5) + cn(2,5) + cn(3,5) and 0 < cn(0,5) + cn(4,5) + cn(2,5) + cn(3,5).at n=34A039903
- Least number m such that the arithmetic mean of the distinct prime divisors of m is equal to 2^n.at n=10A070009
- a(0) = 0, a(1) = a(2) = 1, a(3) = 2, a(4) = 4, a(5) = 8, a(6) = 16, for n>5: a(n+1) = SORT[ a(n) + a(n-1) + a(n-2) + a(n-3) + a(n-4) + a(n-5) + a(n-6)], where SORT places digits in ascending order and deletes 0's.at n=45A108567
- a(n) = least m such that sum of m reciprocal primes starting with n-th prime is >1.at n=19A137368
- Numbers n such that prime[(n + 1)^2] - prime[n^2] is a perfect square.at n=24A145290
- a(n+1) = A154771(a(n)) = sum of all distinct "valid substrings" of a(n); a(1)=10 (least nontrivial choice).at n=36A154770
- Least semiprime whose sum of prime factors equals 2^n.at n=10A193226
- Least k such that the sum of the distinct prime divisors of k equals m^n for some m > 1.at n=11A194230
- Numbers whose Schwarzian arithmetic derivative is an integer.at n=25A209872
- a(n) = floor( prime(n)^3 / (n*log(n)) ).at n=25A259648
- Odd numbers n such that the sum of the binary digits of n and n^2 both equal 12.at n=7A261593
- G.f.: 1/((1-t^7)^2*(1-t)*(1-t^3)*(1-t^5)*(1-t^9)*(1-t^11)*(1-t^13)).at n=66A266747
- Square array read by antidiagonals: T(m,n) = the number of tight m X n pavings (defined below).at n=31A285357
- Square array read by antidiagonals: T(m,n) = the number of tight m X n pavings (defined below).at n=32A285357
- Least numbers k > 1 such that k'' = n*k', where k' and k'' are the first and the second arithmetic derivatives of k.at n=6A287059
- Number of tight m X n pavings as defined in Knuth's A285357 written as triangle T(m,n), m >= 1, 1 <= n <= m.at n=13A298362
- The number of tight 4 X n pavings.at n=5A336732
- The number of tight 5 X n pavings.at n=4A336734
- Numbers k such that w(k-2), w(k-1), and w(k) are all odd, where w is A336957.at n=5A338070