7142
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 14
- Digital Root
- 5
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 10716
- Proper Divisor Sum (Aliquot Sum)
- 3574
- 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
- 3570
- Möbius Function
- 1
- Radical
- 7142
- 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
- yes
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 31
- 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
- yes
- Odd
- no
Appears in sequences
- a(n) = floor(n*phi^17), where phi is the golden ratio, A001622.at n=2A004932
- a(n) = round(n*phi^17), where phi is the golden ratio, A001622.at n=2A004952
- Numbers k such that the continued fraction for sqrt(k) has period 66.at n=31A020405
- Fibonacci sequence beginning 2, 6.at n=16A022112
- 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 84.at n=8A031582
- Numbers k such that 235*2^k+1 is prime.at n=26A032494
- a(n) = floor(10^5/n).at n=13A033427
- a(n)=(s(n)+3)/10, where s(n)=n-th base 10 palindrome that starts with 7.at n=36A043086
- Triangle read by rows: T(n,k) = number of peakless Motzkin paths of length n having k (1,1) steps starting at level zero (can be easily expressed also in RNA secondary structure terminology).at n=41A089736
- Beginning with 1, minimum value such that gcd(a(2n-1),a(2n)) = 1, gcd(a(2n),a(2n+1))>1 and a(n) > a(n-1).at n=42A091856
- a(n) = gcd(Lucas(n)-1, Fibonacci(n)-1).at n=34A115311
- Numbers k such that k^4 contains a pandigital substring.at n=18A115934
- Half-indexed Lucas numbers second version L(n)=A000032=Lucas numbers a(0)=2, a(1)=2, a(2)=1, a(3)=2, a(4)=3, a(5)=3, a(2n)=L(n), for n>2: a(2n+1)=L(n)+L(n-3)=2*L(n-1) for n>5: a(n)+a(n+2)=a(n+4) a(2n)=L(n), so a(n)=L(n/2).at n=37A127218
- a(1)=2. For n >=2, a(n) = the least integer >= a(n-1) that is not coprime to both a(n-1)+1 and a(n-1).at n=24A140525
- Similar to A072921 but starting with 5.at n=36A152234
- Number of binary strings of length n with no substrings equal to 0000, 0001 or 1001.at n=17A164413
- Numbers k such that k, k^2 - 5, and k^2 + 5 are semiprime.at n=33A173085
- Number of partitions of n containing a clique of size 2.at n=32A183559
- Number of ordered triples (w,x,y) with all terms in {-n,...-1,1,...,n} and -1<=2w+x+y<=1.at n=35A211620
- Sum of all parts that are not the smallest part (counted with multiplicity) of all partitions of n.at n=18A213359