13919
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 23
- Digital Root
- 5
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 14400
- Proper Divisor Sum (Aliquot Sum)
- 481
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 13440
- Möbius Function
- 1
- Radical
- 13919
- 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
- no
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 89
- 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
- a(n) = n*(29*n - 1)/2.at n=31A022286
- Geometric mean of the digits = 3. In other words, the product of the digits is = 3^k where k is the number of digits.at n=36A061427
- Number of ordered quadruples (a,b,c,d) with gcd(a,b,c,d)=1 (1 <= {a,b,c,d} <= n).at n=10A082540
- a(n) = 3*A022004(n) + 8.at n=37A163635
- Numbers k that divide 10^(k+1)-1.at n=39A175203
- Lucas pseudoprimes.at n=12A217120
- Nonprime terms in A210494.at n=15A230214
- Numbers k such that 2*k + 1 divides 2^(k+1) - 1.at n=14A246648
- Numbers whose sum of divisors is equal to the product of the number of divisors of their k first powers, for some k.at n=33A283758
- A sequence of integers from an additive problem with prime numbers.at n=20A348472
- Expansion of e.g.f. exp(exp(x) - 1 + x^2/2).at n=8A360991
- a(n) is the number of distinct solution sets to the quadratic equations u*x^2 + v*x + w = 0 with integer coefficients u, v, w, abs(u) + abs(v) + abs(w) <= n having a negative discriminant.at n=41A381710