13248
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 18
- Digital Root
- 9
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 42
- Divisor Sum
- 39624
- Proper Divisor Sum (Aliquot Sum)
- 26376
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 4224
- Möbius Function
- 0
- Radical
- 138
- Omega Function (Ω)
- 9
- 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
- yes
- Narcissistic Number
- no
- Collatz Steps
- 94
- 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
- no
- Achilles Number
- no
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- yes
- Odd
- no
Appears in sequences
- arcsin(tanh(x)+arctan(x))=2*x+4/3!*x^3+168/5!*x^5+13248/7!*x^7...at n=3A013142
- Least term in period of continued fraction for sqrt(n) is 10.at n=24A031434
- Consider the trajectory of n under the iteration of a map which sends x to 3x - sigma(x) if this is >= 0; otherwise the iteration stops. The sequence gives values of n which eventually reach 0.at n=26A037159
- Numbers whose base-4 representation contains exactly four 0's and three 3's.at n=9A045084
- a(n) = n^3 - n^2.at n=24A045991
- Numbers k such that sigma(x) = k has exactly 8 solutions.at n=32A060664
- Numbers k such that gcd(d(k^3), d(k)) is not a power of 2.at n=37A069781
- Smallest number k for which the set of solutions to phi(x) = k has 2n-1 entries.at n=36A071387
- Least number m such that cardinality of InvPhi(m) = prime(n).at n=20A071389
- a(n) = A074639(A074645(n)).at n=21A074646
- Coefficients in expansion of Eisenstein series -q*E'_2.at n=22A076835
- Expansion of (1-x)/(1-2*x+2*x^2+2*x^3).at n=17A078005
- (n / product of digits of n) is a semiprime.at n=33A085773
- a(n) = binomial(n,3) - binomial(floor(n/2),3) - binomial(ceiling(n/2),3).at n=48A111384
- a(n) = n*(n+1)^2.at n=22A114364
- Inverse Moebius transform of the shifted tetrahedral numbers.at n=40A116963
- Lower triangular array, called S1hat(-4), related to partition number array A145369.at n=57A145370
- a(n) = 529*n^2 + 23.at n=5A158631
- Numbers n with property that n^2 is a sum of some 120 successive primes.at n=4A166262
- Worpitzky form polynomials for the {1,16,1} A142462 sequence: p(x,n) = Sum_{k=1..n} A(n, k)*binomial(x + k - 1, n - 1).at n=13A168296