7171
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 16
- Digital Root
- 7
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 4
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 7344
- Proper Divisor Sum (Aliquot Sum)
- 173
- 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
- 7000
- Möbius Function
- 1
- Radical
- 7171
- 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
- 75
- 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
- Pentagonal numbers written backwards.at n=34A004163
- Numbers that are the sum of 10 positive 10th powers.at n=7A004810
- Pseudoprimes to base 14.at n=26A020142
- Pseudoprimes to base 17.at n=26A020145
- Strong pseudoprimes to base 14.at n=6A020240
- Strong pseudoprimes to base 17.at n=11A020243
- Lucky numbers that are concatenations of a number k with itself.at n=7A032650
- Numbers whose base-4 representation contains exactly four 0's and two 3's.at n=15A045083
- Numbers whose consecutive digits differ by 6.at n=28A048408
- Triangle T(n,k) giving number of 3 X k polyominoes with n cells (n >= 3, 1<=k<=n-2).at n=75A059683
- a(n) = 6*n^2 + 6*n + 31.at n=34A060834
- Partial sums of A068058 + 1.at n=36A068059
- a(n) = Sum_{i=n+1..2n} prime(i) - Sum_{i=1..n} prime(i).at n=36A077354
- Take pairs (a, b), sorted on a, such that T(a)+T(b)=concatenation of a and b, where T(k) is the k-th triangular number A000217(k). Sequence gives values of b.at n=12A096032
- Take pairs (a, b), sorted on a, such that T(a)+T(b)=concatenation of a and b, where T(k) is the k-th triangular number A000217(k). Sequence gives values of b.at n=27A096032
- Semiprimes (A001358) whose digit reversal is a pentagonal number (A000326).at n=16A115708
- Triangle read by rows: T(n,k) is the number of deco polyominoes of height n having k cells in the second column (n>=1, k>=0). A deco polyomino is a directed column-convex polyomino in which the height, measured along the diagonal, is attained only in the last column.at n=32A121581
- Number of subtrees of a complete binary tree.at n=22A157679
- a(n) = 7*2^n + 3.at n=10A164285
- Number of binary strings of length n with no substrings equal to 0001, 0100, or 0111.at n=16A164464