6789
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 30
- Digital Root
- 3
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 9472
- Proper Divisor Sum (Aliquot Sum)
- 2683
- 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
- 4320
- Möbius Function
- -1
- Radical
- 6789
- Omega Function (Ω)
- 3
- Little Omega Function (ω)
- 3
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
- yes
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 36
- 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
- no
- Odd
- yes
Appears in sequences
- a(n) = F(n+2) + c(n) where F(k) is k-th Fibonacci number and c(n) is n-th number that is 1 or is a non-Fibonacci number.at n=17A022800
- a(n) = b(n) + d(n), where b(n) = (n-th Fibonacci number > 2) and d(n) = (n-th non-Fibonacci number).at n=16A023486
- a(n) = b(n) + d(n), where b(n) = (n-th Fibonacci number > 1) and d(n) = (n-th non-Lucas number).at n=17A023491
- Numbers k such that the continued fraction for sqrt(k) has even period and if the last term of the periodic part is deleted the central term is 54.at n=32A031552
- Numbers with exactly five distinct base-9 digits.at n=20A031986
- McKay-Thompson series of class 29A for Monster.at n=30A058611
- Numbers in which each digit is the (immediate) successor of the previous one (if it exists) and 0 is considered the successor of 9.at n=33A059043
- Smallest number that has digits in order ...123...901... and is divisible by n. If no such number exists then a(n) = 0.at n=30A061805
- a(n) = (10^n-1)*(91/81)-n*10^n/9.at n=3A064616
- Trajectory of n under the Reverse and Add! operation carried out in base 3 (presumably) does not reach a palindrome and (presumably) does not join the trajectory of any term m < n.at n=22A077405
- Concatenation of next n numbers (a(1) = 0).at n=3A080481
- a(1) = 1; for n > 1, a(n) > a(n-1) is the smallest number such that the concatenation a(1)a(2)a(3)... forms a cyclic concatenation of 123456789 (of nonzero digits).at n=18A081549
- Numbers n such that 9*10^n-7 is prime.at n=18A103092
- a(1) = 10; a(n) is smallest number >= a(n-1) such that the juxtaposition a(1)a(2)...a(n) is a prime.at n=34A111524
- a(n) = (p-1)! mod p^2 where p = n-th prime.at n=24A112660
- Numbers k such that k and 8*k, taken together, are zeroless pandigital.at n=16A115932
- Lucky numbers with consecutive digits.at n=7A118569
- Concatenation of 3 or more numbers in arithmetic progression with positive common difference.at n=40A119426
- Numbers n such that every digit occurs at least once in n^3.at n=19A119735
- Number of integer-sided pentagons having perimeter n.at n=40A124285