7289
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 26
- Digital Root
- 8
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 7524
- Proper Divisor Sum (Aliquot Sum)
- 235
- 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
- 7056
- Möbius Function
- 1
- Radical
- 7289
- 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
- 119
- 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
- a(n) = Sum_{k=0..n-1} T(n,k) * T(n,k+1), with T given by A026648.at n=6A026972
- Numbers having three 8's in base 9.at n=32A043487
- a(n)=T(n,n+2), array T as in A049735.at n=33A049742
- Numbers k such that k^8 == 1 (mod 9^3).at n=19A056084
- Composite and every divisor (except 1) contains the digit 7.at n=37A062676
- a(n) is the smallest k such that (k^3 + 1)/(n^3 + 1) is an integer > 1.at n=28A065964
- Numerator of Sum_{k=1..n} k/phi(k).at n=16A068885
- Numbers n such that the trajectory of n under the `3x+1' map reaches n - 1.at n=40A070991
- Smaller terms in the pairs of numbers (a < b) in the sequence {a,b}-> {Max[{a,b}]-Min[{a,b}],k*Min[{a,b}]} with k=3 and the first pair {a=1,b=2}. See A075256.at n=38A075257
- Sum of terms in n-th rows of triangle in A077159.at n=24A077162
- Row sums of A081964.at n=24A081966
- Numbers n such that 2^n+25229 is prime.at n=51A103148
- The sum of a triangular array made from a negative 6-fold permutation product.at n=11A105156
- a(n) = prime(n) * Sum_{i=1..n} prime(i).at n=11A143215
- Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, -1, -1), (-1, 0, 1), (0, 1, 0), (1, 0, 0), (1, 1, -1)}.at n=8A149882
- Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, -1, 0), (-1, 0, 0), (0, 0, 1), (0, 1, 0), (1, 0, -1)}.at n=8A149887
- Triangle read by rows: T(n,k) is the number of Dyck paths of semilength n having k peaks of maximum height (1 <= k <= n).at n=57A152879
- a(n) = 729*n - 1.at n=9A158395
- a(n) = 10*n^2 - 1.at n=26A158447
- Totally multiplicative sequence with a(p) = a(p-1) + 8 for prime p.at n=22A166705