13902
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
- 1
Divisibility
- Divisor Count
- 16
- Divisor Sum
- 31872
- Proper Divisor Sum (Aliquot Sum)
- 17970
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 3960
- Möbius Function
- 1
- Radical
- 13902
- 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
- no
- Narcissistic Number
- no
- Collatz Steps
- 112
- 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
- yes
- Odd
- no
Appears in sequences
- a(n) = dot_product(1,2,...,n)*(5,6,...,n,1,2,3,4).at n=31A026043
- 4n^2+1, 2n^2+1, 2n^2-1 are all prime.at n=33A055755
- Numbers n such that sigma(n) - sigma(reverse(n)) = phi(n).at n=2A071847
- Numbers k such that k-1, k+1, and k^2-k-1 are primes.at n=43A154666
- Numerator of Euler(n, 3/17).at n=4A156533
- Row sums of triangle defined in A113821.at n=29A160969
- Smallest a(n) such that the prime factorization of a(n)! contains at least one factor to each exponent between 1 and n.at n=44A177442
- Position of 5^n in A051037 (5-smooth numbers).at n=28A188427
- Number of n X n 0..1 arrays avoiding 0 0 0 and 1 1 1 horizontally and 0 0 1 and 1 0 0 vertically.at n=4A207655
- Number of nX5 0..1 arrays avoiding 0 0 0 and 1 1 1 horizontally and 0 0 1 and 1 0 0 vertically.at n=4A207658
- T(n,k)=Number of nXk 0..1 arrays avoiding 0 0 0 and 1 1 1 horizontally and 0 0 1 and 1 0 0 vertically.at n=40A207661
- Number of 5Xn 0..1 arrays avoiding 0 0 0 and 1 1 1 horizontally and 0 0 1 and 1 0 0 vertically.at n=4A207663
- Triangle read by rows: coefficients of polynomials p_{n,n-1}(x) arising in enumeration of two-line arrays.at n=50A212207
- Expansion of Product_{k>=0} ((1+x^(3*k+1))/(1-x^(3*k+1)))^3.at n=15A261651
- Growth series for group with presentation < S, T : S^2 = T^3 = (S*T)^10 = 1 >.at n=27A298812
- a(n) = Sum_{k=1..n} k^2 * tau(k)^2, where tau is A000005.at n=13A320897
- Products of four distinct primes between twin primes.at n=38A353022