7139
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 20
- Digital Root
- 2
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 4
Divisibility
- Divisor Count
- 6
- Divisor Sum
- 7980
- Proper Divisor Sum (Aliquot Sum)
- 841
- 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
- 6380
- Möbius Function
- 0
- Radical
- 649
- Omega Function (Ω)
- 3
- 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
- 75
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- no
- Squarefree Number
- no
- 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
- 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 83.at n=25A031581
- Numbers k such that 255*2^k+1 is prime.at n=31A032504
- Numbers whose set of base-13 digits is {2,3}.at n=28A032813
- Denominators of continued fraction convergents to sqrt(74).at n=10A041131
- If p | n, then p+1 | n+1 for composite n.at n=37A056729
- Fourth column (r=3) of FS(3) staircase array A062745.at n=32A062748
- Number of permutations satisfying -k<=p(i)-i<=r and p(i)-i not in I, i=1..n, with k=3, r=3, I={-2,1,2}.at n=17A079983
- a(n) = 6*n*(n-1) - 1.at n=35A103115
- Numerator of sum of reciprocals of first n pentatope numbers A000332.at n=32A118411
- a(n) = 4*n^2 - 6*n + 1.at n=42A125202
- a(n) = (1 + 3*n)*(4 + 3*n)/2.at n=39A145910
- Number of planar n X n X n binary triangular grids with mirror symmetry about one altitude with no more than 3 ones in any 5 X 5 X 5 subtriangle.at n=9A153927
- a(n) = a(n-1) + a(n-2) - [a(n-2)/4] - [a(n-4)/2] - [a(n-6)/4].at n=30A173599
- a(n) = 8*n^2 + 14*n + 5.at n=29A181890
- a(n) is the number whose binary representation is the concatenation of the divisors of n written in base 2.at n=34A182622
- a(n) = 11*a(n-1) - 22*a(n-2), a(0)=0, a(1)=1.at n=5A190870
- a(n) = (6*n^2 + 7*n - 9 + 2*n^3)/12 - (-1)^n*(n+1)/4.at n=33A219527
- Number of cyclotomic cosets of 11 mod 10^n.at n=29A220021
- Numerator of Sum_{k=1..n} 1/(k(k+1)(k+2)(k+3)) = Sum_{k=1..n} 1/Pochhammer(k,4).at n=33A230339
- a(n) = Sum_{i=0..n} digsum_3(i)^4, where digsum_3(i) = A053735(i).at n=38A231505