11637
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 18
- Digital Root
- 9
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 17280
- Proper Divisor Sum (Aliquot Sum)
- 5643
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 7740
- Möbius Function
- 0
- Radical
- 1293
- Omega Function (Ω)
- 4
- 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
- 50
- 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
- a(1) = 2; a(n+1) = a(n)-th nonprime, where nonprimes begin at 1.at n=35A025003
- Larger members of g-reduced amicable pairs a < b such that sigma(a) = sigma(b) = a + b + gcd(a,b).at n=30A054572
- Positive numbers whose product of digits is 7 times their sum.at n=26A062384
- Largest integer not expressible as a nonnegative linear combination of n and n^2 + 1.at n=22A087908
- a(n) = 2*n^3 - 2*n + 9.at n=17A127989
- a(n) = (4*n^4 - 4*n^3 - n^2 + 3*n)/2.at n=8A135400
- As a vector, shifts to the left when multiplied by A054521.at n=27A147524
- a(n) = n^3 - 3*(n+3)^2.at n=24A153260
- Number of ways to place zero or more nonadjacent 0,0 1,0 2,1 3,1 3,2 4,2 5,2 6,3 polyhexes in any orientation on a planar nXnXn triangular grid.at n=7A155416
- a(n) = 16*n^2 - n.at n=26A157446
- a(n) = 529*n - 1.at n=21A158365
- a(n) = 22*n^2 - 1.at n=22A158540
- a(n) = 729*n^2 - 27.at n=3A158655
- Triangle read by rows: T(n,k) is the number of permutations of {1,2,...,n} having k double descents and initial descents (n>=0; 0<=k<=max(0,n-1)) [we say that i is a doubledescent of a permutation p if p(i) > p(i+1) > p(i+2); we say that a permutation p has an initial descent if p(1) > p(2)].at n=31A162976
- Number of binary strings of length n with no substrings equal to 0011 0101 or 1100.at n=16A164505
- Number of permutations of 1..n avoiding adjacent step pattern up, down, up.at n=8A177477
- Number of n X n binary arrays without the pattern 0 0 1 diagonally, vertically or antidiagonally.at n=3A189689
- Number of nX4 binary arrays without the pattern 0 0 1 diagonally, vertically or antidiagonally.at n=3A189691
- T(n,k)=Number of nXk binary arrays without the pattern 0 0 1 diagonally, vertically or antidiagonally.at n=24A189696
- Number of 4Xn binary arrays without the pattern 0 0 1 diagonally, vertically or antidiagonally.at n=3A189697