11281
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 13
- Digital Root
- 4
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 11700
- Proper Divisor Sum (Aliquot Sum)
- 419
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 10864
- Möbius Function
- 1
- Radical
- 11281
- 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
- 86
- 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
- a(n) = 2nd elementary symmetric function of {1, prime(1), prime(2), ..., prime(n-1)}, where prime(0) = 1.at n=10A024522
- Number of partitions satisfying cn(2,5) <= 1 and cn(3,5) <= 1.at n=42A039855
- Denominators of continued fraction convergents to sqrt(778).at n=8A042501
- a(n) = Sum_{i=0..2n} (-1)^i * T(i,2n-i), array T as in A049735.at n=30A049737
- Numbers k such that the continued fraction of (1 + sqrt(k))/2 has period 15.at n=40A146338
- Number of n X n binary arrays with all ones connected only in a 0100-0100-1111-0010 pattern in any orientation.at n=7A147027
- Number of n X n binary arrays symmetric under horizontal and vertical reflection with all ones connected only in a 0100-0100-1111-0010 pattern in any orientation.at n=16A147029
- Number of n X n binary arrays symmetric under horizontal and vertical reflection with all ones connected only in a 0100-0100-1111-0010 pattern in any orientation.at n=17A147029
- Number of partitions of n into as many primes as nonprimes.at n=49A155515
- Expansion of x*(1+2*x+8*x^2+4*x^3+3*x^4) / ( (1+x)^2*(x-1)^4 ).at n=24A178947
- Fundamental discriminants of real quadratic number fields with class number 10.at n=23A218160
- E.g.f.: Sum_{n>=0} exp(n*2^n*x) * x^n/n!.at n=5A244820
- Total number of lambda-parking functions induced by all partitions of n into distinct parts.at n=19A265202
- Odd powers of 2 written between a pair of 1's.at n=3A268519
- Partial sums of A299255.at n=18A299261
- Number of nX7 0..1 arrays with every element unequal to 0, 2, 3, 5 or 8 king-move adjacent elements, with upper left element zero.at n=7A305359
- Numbers m such that m = p^2 + k^2, with p > 0, where p = A007954(m) = the product of digits of m.at n=15A334557
- Odd composite integers m such that A087130(m) == 5 (mod m).at n=21A335671
- a(n)/A002939(n+1) is the Kirchhoff index of the join of the disjoint union of two complete graphs on n vertices with the empty graph on n+1 vertices.at n=8A338109
- Centered 10-gonal numbers which are products of two primes.at n=19A367792