7669
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 28
- Digital Root
- 1
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 4
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 7670
- Proper Divisor Sum (Aliquot Sum)
- 1
- 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
- 7668
- Möbius Function
- -1
- Radical
- 7669
- Omega Function (Ω)
- 1
- Little Omega Function (ω)
- 1
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
- yes
- Composite Number
- no
- Semiprime
- no
- Squarefree Number
- yes
- Prime Power
- yes
- Prime Factorization
- no
- Twin Prime
- no
- Mersenne Prime
- no
- Sophie Germain Prime
- no
- Safe Prime
- no
- Powerful Number
- no
- Achilles Number
- no
- Prime Index
- 972
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Number of numbers of complexity n, i.e., that can be built from n ones using + and *, and require at least that many ones.at n=30A005421
- Coordination sequence for sigma-CrFe, Position Xa.at n=22A009962
- E.g.f.: cos(sinh(x)+log(x+1))=1-4/2!*x^2+6/3!*x^3-11/4!*x^4+10/5!*x^5...at n=8A013018
- Number of triples of different integers from [ 2,n ] with no global factor.at n=38A015618
- Numbers k such that the continued fraction for sqrt(k) has period 55.at n=7A020394
- Primes that remain prime through 3 iterations of function f(x) = 9x + 10.at n=28A023299
- Least m such that if r and s in {1/3, 1/6, 1/9, ..., 1/3n} satisfy r < s, then r < k/m < (k+1)/m < s for some integer k.at n=38A024838
- Upper prime of a difference of 20 between consecutive primes.at n=9A031939
- Numbers whose base-4 representation contains exactly four 1's and three 3's.at n=15A045132
- a(1) = 7; a(n) is smallest number >= a(n-1) such that the juxtaposition a(1)a(2)...a(n) is a prime.at n=47A046257
- Primes whose sum of digits is the perfect number 28.at n=12A048517
- Smallest prime p having n different cycles in decimal expansions of k/p, k=1..p-1.at n=26A054471
- Number of lucky twins <= 10^n.at n=6A055724
- Primes p that have exactly two primitive roots that are not primitive roots mod p^2.at n=38A060518
- Primes with either no internal digits or all internal digits are 6.at n=47A069681
- Positions of zero in the infinite audioactive word, A088205, which shifts left under "Look and Say" method A, starting with a(1)=0.at n=25A088206
- Primes of the form 6*p - 5 such that p and 6*p - 1 are primes.at n=33A090607
- Primes with minimal digit = 6.at n=12A106106
- Primes having only {6, 7, 8, 9} as digits.at n=22A106111
- Smallest prime factor of the reverse concatenation of the first n odd numbers.at n=29A109837