1385
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 17
- Digital Root
- 8
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 1668
- Proper Divisor Sum (Aliquot Sum)
- 283
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Highly Composite
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 1104
- Möbius Function
- 1
- Radical
- 1385
- 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
- 65
- 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
- Euler or up/down numbers: e.g.f. sec(x) + tan(x). Also for n >= 2, half the number of alternating permutations on n letters (A001250).at n=8A000111
- Euler (or secant or "Zig") numbers: e.g.f. (even powers only) sec(x) = 1/cos(x).at n=4A000364
- Number of permutations of [n] with exactly 3 increasing runs of length at least 2.at n=1A000507
- a(n) = 3*n^2 + 3*n - 1.at n=21A004538
- Related to representations as sums of Fibonacci numbers.at n=31A006133
- Boustrophedon version of triangle of Euler-Bernoulli or Entringer numbers read by rows.at n=37A008280
- Boustrophedon version of triangle of Euler-Bernoulli or Entringer numbers read by rows.at n=36A008280
- Boustrophedon version of triangle of Euler-Bernoulli or Entringer numbers read by rows.at n=46A008280
- Triangle of Euler-Bernoulli or Entringer numbers read by rows.at n=43A008281
- Triangle of Euler-Bernoulli or Entringer numbers read by rows.at n=46A008281
- Triangle of Euler-Bernoulli or Entringer numbers read by rows.at n=44A008281
- Triangle of Euler-Bernoulli or Entringer numbers read by rows: T(n,k) is the number of down-up permutations of n+1 starting with k+1.at n=35A008282
- Triangle of Euler-Bernoulli or Entringer numbers read by rows: T(n,k) is the number of down-up permutations of n+1 starting with k+1.at n=34A008282
- Triangle of Euler-Bernoulli or Entringer numbers read by rows: T(n,k) is the number of down-up permutations of n+1 starting with k+1.at n=36A008282
- Read across rows of Euler-Bernoulli or Entringer triangle.at n=21A008283
- Triangle of coefficients in expansion of D^n (sec x) / sec x in powers of tan x.at n=20A008294
- Triangle of coefficients in expansion of D^n (sec x) / sec x in powers of tan x.at n=16A008294
- Triangle T(n,k) = P(n,k)/2, n >= 2, 1 <= k < n, of one-half of number of permutations of 1..n such that the differences have k runs with the same signs.at n=27A008970
- Triangle read by rows: T(n,k) is the number of permutations of [n] with k increasing runs of length at least 2.at n=24A008971
- Triangle read by rows: T(n,k) is the number of permutations of [n] with k increasing runs of length at least 2.at n=19A008971