7189
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 25
- Digital Root
- 7
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 8960
- Proper Divisor Sum (Aliquot Sum)
- 1771
- 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
- 5616
- Möbius Function
- -1
- Radical
- 7189
- 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
- no
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 119
- 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) = (n^4 + n^2 + 2*n)/4.at n=13A006528
- Pseudoprimes to base 23.at n=44A020151
- Pseudoprimes to base 24.at n=28A020152
- Pseudoprimes to base 55.at n=32A020183
- Pseudoprimes to base 80.at n=41A020208
- Numbers k such that the continued fraction for sqrt(k) has period 72.at n=25A020411
- Graham-Sloane-type lower bound on the size of a ternary (n,3,4) constant-weight code.at n=26A030504
- Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 36 ones.at n=32A031804
- Indices of 9-gonal numbers which are also pentagonal.at n=2A048913
- a(n) = Sum{a(k): k=0,1,2,...,n-4,n-2,n-1}; a(n-3) is not a summand; initial terms are 1,2,2.at n=15A049868
- Numbers that are sums of divisors of the odd squares; Intersection of A065764 and A065766, written in ascending order and duplicates removed.at n=38A065768
- Numbers k such that the simple continued fraction for (1+1/k)^k contains k.at n=48A071527
- Numbers k such that k^4 = x^3 + y^2 has an integer solution.at n=28A096741
- Define a(1)=1. Thereafter a(n) is the smallest positive integer with the property that a(n)^2 cannot be created by summing the squares of at most n values chosen among the previous terms (with repeats allowed).at n=17A111302
- Generalized Mancala solitaire (A002491); to get n-th term, start with n and successively round up to next 8 multiples of n-1, n-2, ..., 1, for n>=1.at n=43A113745
- Difference between first twin prime > 10^n and 10^n.at n=31A124001
- Number of walks from (0,0) to (n,n) in the region 0 <= x-y <= 3 with the steps (1,0), (0, 1), (2,0) and (0,2).at n=7A127617
- The first 8 values are predefined, the remaining set to a(n) = 48*prime(n)+n+2.at n=34A129025
- Products of three distinct happy primes A035497.at n=7A154717
- Products of three distinct primes of the form 6*k + 1.at n=10A154729