11270
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 11
- Digital Root
- 2
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 24
- Divisor Sum
- 24624
- Proper Divisor Sum (Aliquot Sum)
- 13354
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 3696
- Möbius Function
- 0
- Radical
- 1610
- Omega Function (Ω)
- 5
- Little Omega Function (ω)
- 4
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
- 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
- Numbers k where the fractional part of tan(k) decreases monotonically to 0.at n=6A016274
- a(n) = 1*t(n) + 2*t(n-1) + ... + k*t(n+1-k), where k=floor((n+1)/2) and t(n)=2*n+1 (odd numbers).at n=39A023865
- a(n) = s(1)*t(n) + s(2)*t(n-1) + ... + s(k)*t(n-k+1), where k = floor(n/2), s = natural numbers, t = odd natural numbers.at n=38A024862
- a(n) = 2^(n-1)*(6*n-10)+6.at n=9A048499
- a(n) = Sum_{k=1..floor((n+1)/2)} T(n,2k-1), array T as in A049777.at n=39A049778
- Sum of n-th antidiagonal of array in A082002.at n=22A082005
- a(n) = sum of the first n upper twin primes.at n=33A086168
- Expansion of 1/((1-x)^2*(1-x^2)^2*(1-x^3)).at n=38A097701
- 2^(n-1) times coefficient of x in (1+x)^n mod U(n,x), U the Chebyshev polynomials.at n=10A099590
- a(1)=1. a(n) = a(n-1) + (largest integer occurring among {a(1),a(2),a(3),...,a(n-1)} that is coprime to n).at n=18A120939
- Numbers k such that 6*p(k)*p(k+1)*p(k+2)*p(k+3)*p(k+4)*p(k+5)-1 and 6*p(k)*p(k+1)*p(k+2)*p(k+3)*p(k+4)*p(k+5)+1 are twin primes with p(h) = h-th prime.at n=17A129311
- a(n) = n*(n+1)*(8*n + 1)/6.at n=20A132124
- Numbers k such that k and k^2 use only the digits 0, 1, 2, 7 and 9.at n=27A136833
- a(n) = 289*n - 1.at n=38A158253
- Even almost practical numbers.at n=39A174534
- Describe 10^n. Also called the "Say What You See" or "Look and Say" sequence LS(10^n).at n=27A191111
- G.f.: A(x) = 1 + Sum_{n>=1} x^n*A(x)^(3^(n-1)).at n=7A195259
- Number of all possible tetrahedra of any size and orientation, formed when intersecting the original regular tetrahedron by planes parallel to its sides and dividing its edges into n equal parts.at n=19A216173
- Number of n-digit numbers N such that the reversal of N divides N but is different from N.at n=7A222809
- Numbers n whose Zeckendorf representation is of the form ww, for w a nonempty block of digits.at n=55A286710