7664
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 23
- Digital Root
- 5
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 10
- Divisor Sum
- 14880
- Proper Divisor Sum (Aliquot Sum)
- 7216
- 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
- 3824
- Möbius Function
- 0
- Radical
- 958
- Omega Function (Ω)
- 5
- 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
- 57
- 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
- Number of down-up permutations of n+3 starting with n+1.at n=7A006212
- Boustrophedon version of triangle of Euler-Bernoulli or Entringer numbers read by rows.at n=52A008280
- Triangle of Euler-Bernoulli or Entringer numbers read by rows.at n=52A008281
- 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=42A008282
- Read across rows of Euler-Bernoulli or Entringer triangle.at n=27A008283
- Expansion of tan(x)/(1+x).at n=7A009753
- Triangle of Euler-Bernoulli or Entringer numbers.at n=38A010094
- a(n) = n*(15*n - 1)/2.at n=32A022272
- a(n) = Sum_{k=0..2n-3} T(n,k) * T(n,k+3), with T given by A026568.at n=3A027280
- Number of binary [ n,6 ] codes.at n=11A034360
- Expansion of 1 + x/(1 - 2*x - x^3 + x^4).at n=13A052908
- Triangle read by rows: this is a variant of A008280 in which 2 rows go from left to right, 2 from right to left, 2 from left to right, etc.at n=63A058257
- Expansion of series related to Liouville's Last Theorem: g.f. Sum_{t>0} (-1)^(t+1) *x^(t*(t+1)/2) / ( (1-x^t)^3 *Product_{i=1..t} (1-x^i) ).at n=40A059820
- Triangle in which rows are permutations of the rows of A008282.at n=40A064192
- a(n) = 16*(8*prime(n) + 7).at n=16A098823
- Reflection of triangle in A008280 in vertical axis.at n=47A108040
- Positive numbers that are not the sum of two squares and a positive Fibonacci number.at n=21A115176
- n times n+9 gives the concatenation of two numbers m and m-8.at n=4A116240
- Numbers k such that A136675(k) is prime.at n=28A136683
- a(n) = 512*n - 16.at n=14A157447