7889
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 32
- Digital Root
- 5
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 9600
- Proper Divisor Sum (Aliquot Sum)
- 1711
- 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
- 6468
- Möbius Function
- 0
- Radical
- 161
- Omega Function (Ω)
- 4
- 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
- 101
- 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
- no
- Odd
- yes
Appears in sequences
- a(n) = C(n,5) + C(n,4) - C(n,3) + 1, n >= 7.at n=11A005288
- Numbers k such that k divides the (left) concatenation of all numbers <= k written in base 11 (most significant digit on right and removing all least significant zeros before concatenation).at n=7A029528
- Numerators of continued fraction convergents to sqrt(254).at n=4A041476
- a(n) = 4*n*a(n-1) + 1 with a(0)=1.at n=4A056545
- Numbers n such that n | 10^n + 9^n + 8^n + 7^n + 6^n + 5^n + 4^n.at n=8A057266
- Sum of digits = 8 times number of digits.at n=19A061425
- Take pairs (x,y) with Sum_{j = x..y} j = concatenation of x and y. Sort pairs on y then x. This sequence gives y of each pair.at n=18A070153
- Number of sorted multiplicative partitions of n! of length n.at n=18A085289
- Smallest number not occurring earlier fitting the repeating pattern "11223344556677889900".at n=40A098781
- a(n) = a(n-1)+a(n-2)+3a(n-3), with a(0)=a(1)=a(2)=1.at n=13A099213
- a(n) = a(n-1) + a(n-2) + 7 where a(0) = a(1) = 1.at n=15A111733
- Numbers (excluding primes and powers of primes) such that the square mean of their prime factors is a prime (where the square mean of c and d is sqrt((c^2+d^2)/2)).at n=36A134604
- Composite numbers such that the square root of the sum of squares of their prime factors (with multiplicity) is an integer.at n=38A134605
- Numbers such that the square root of the sum of squares of their prime factors is a nonprime integer.at n=30A134606
- Define f(n) by e(n+1) = e(n) + 3^{n+1} - 1 + 2*f(n), where the rational numbers e(n) are defined in A134939; then a(n) is the numerator of f(n).at n=3A134940
- Numbers k such that the number of digits d in k^2 is not prime and for each factor f of d the sum of the d/f digit groupings in k^2 of size f is a square.at n=23A153745
- Numbers k such that there are 8 digits in k^2 and for each factor f of 8 (1,2,4) the sum of digit groupings of size f is a square.at n=13A153746
- Number of reduced words of length n in the Weyl group A_14.at n=5A161475
- Twin natural nonprimes with nonprime number of prime factors.at n=29A171995
- Number of partitions p of n such that max(p)-min(p) = 7.at n=37A218570