7141
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 13
- Digital Root
- 4
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 7372
- Proper Divisor Sum (Aliquot Sum)
- 231
- 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
- 6912
- Möbius Function
- 1
- Radical
- 7141
- 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
- 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
- no
- Odd
- yes
Appears in sequences
- Centered 12-gonal numbers, or centered dodecagonal numbers: numbers of the form 6*k*(k-1) + 1.at n=34A003154
- Pseudoprimes to base 63.at n=24A020191
- Pseudoprimes to base 84.at n=21A020212
- Pseudoprimes to base 85.at n=45A020213
- Strong pseudoprimes to base 84.at n=6A020310
- Strong pseudoprimes to base 85.at n=7A020311
- Numbers k such that the continued fraction for sqrt(k) has period 77.at n=4A020416
- a(n) = a(n-1) + a(n-2) + 1 for n > 1, a(0)=1, a(1)=5.at n=16A022319
- Numerator of -Sum_{k=1..n} (-1)^k / prime(k).at n=6A024530
- a(n) = least m such that if r and s in {1/2, 1/4, 1/6, ..., 1/2n} satisfy r < s, then r < k/m < (k+1)/m < s for some integer k.at n=45A024835
- a(n) = least m such that if r and s in {1/2, 1/4, 1/6, ..., 1/2n} satisfy r < s, then r < k/m < (k+2)/m < s for some integer k.at n=36A024842
- Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 40 ones.at n=34A031808
- "EGJ" (unordered, element, labeled) transform of 2,1,1,1...at n=9A032313
- Numbers whose set of base-13 digits is {3,4}.at n=15A032837
- Least k such that A033178(k)=n.at n=42A038004
- a(n) = n*(n^2 - 6*n + 11)/6.at n=37A050407
- Discriminants of real quadratic fields with class number 2 and related continued fraction period length of 21.at n=12A051986
- a(n) = 4*n^2 - 6*n + 3.at n=42A054569
- Composite numbers not divisible by 2 or 3 which in base 3 contain their largest proper factor as a substring.at n=13A063132
- Duplicate of A063132.at n=13A063874