6928
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
- 4
Divisibility
- Divisor Count
- 10
- Divisor Sum
- 13454
- Proper Divisor Sum (Aliquot Sum)
- 6526
- 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
- 3456
- Möbius Function
- 0
- Radical
- 866
- Omega Function (Ω)
- 5
- 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
- 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
- yes
- Odd
- no
Appears in sequences
- arcsinh(sec(x)*arctanh(x))=x+4/3!*x^3+28/5!*x^5+152/7!*x^7+6928/9!*x^9...at n=4A012847
- Expansion of (theta_3(z)*theta_3(13z)+theta_2(z)*theta_2(13z))^4.at n=40A028620
- [ exp(7/22)*n! ].at n=6A030835
- Gaps of 10 in sequence A038593 (lower terms).at n=5A038659
- Numbers ending with '8' that are the difference of two positive cubes.at n=26A038863
- (n+4)^3 - n^3.at n=21A038866
- Bessel function |Y_0(n)| is a monotonically decreasing positive sequence.at n=29A046963
- Triangle read by rows: T(n,k) = Sum_{j=0..k-1} T(n,j) + Sum_{j=1..n-k} T(n-j,k), with T(0,0)=1 and T(n,k) = 0 for k > n.at n=39A059450
- Number of inequivalent binary linear codes of length n. Also the number of nonisomorphic binary matroids on an n-set.at n=11A076766
- Number of permutations satisfying -k<=p(i)-i<=r and p(i)-i not in I, i=1..n, with k=1, r=4, I={0,2}.at n=31A079974
- Number of partitions of n^2 into squares providing no dissections of the square n X n into smaller squares.at n=13A092179
- Total number of largest parts in all partitions of n into odd parts.at n=52A092311
- Numbers n such that more than half of the reduced-residue system modulo 210 consists of primes in the following sense: in {210n + R} more than 24 = phi(210)/2 primes occur, i.e., 25-33, 35, 46.at n=54A095392
- a(1)=1. a(n) = a(n-1) + (sum of the terms, from among terms a(1) through a(n-1), which are coprime to sum{k=1 to n-1} a(k)).at n=10A131347
- Triangle, read by rows of 2n+1 terms, where T(n,k) = T(n,k-1) + T(n-1,k-2) for n>0, 1<k<=2n, with T(n,1)=T(n,0)=T(n-1,2n-2) for n>0 and T(0,0)=1.at n=55A132427
- a(n) is the smallest number m such that phi(m)+sigma(m)=n*pi(m).at n=16A145747
- Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, 0, 0), (0, -1, 0), (0, 1, -1), (1, 1, 1)}.at n=8A149425
- a(n) = 169*n - 1.at n=40A158219
- Number of n X 2 1..4 arrays with all 1's connected, all 2's connected, all 3's connected, all 4's connected, 1 in the upper left corner, 2 in the upper right corner, 3 in the lower left corner, 4 in the lower right corner, and with no element having more than 2 neighbors with the same value.at n=41A164754
- The initial decimal digits of 2^a(n) are the decimal digits of n followed by n.at n=33A171652