11935
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 19
- Digital Root
- 1
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 16
- Divisor Sum
- 18432
- Proper Divisor Sum (Aliquot Sum)
- 6497
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 7200
- Möbius Function
- 1
- Radical
- 11935
- Omega Function (Ω)
- 4
- 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
- yes
- 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
- 99
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- no
- 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) = n*(n+1)*(2*n+1)*(3*n+1)/6.at n=10A011195
- Geometric mean of phi(n) and sigma(n) is an integer, n odd.at n=29A015705
- Numbers k such that sigma(k) = sigma(k+3).at n=2A015861
- From George Gilbert's marks problem: jumping 3 marks at a time (initial positions).at n=9A019593
- Odd 10-gonal (or decagonal) numbers.at n=27A028993
- a(n) = (2*n-1)*(4*n-1).at n=39A033567
- Triangular numbers that have some nontrivial permutation of digits which is also triangular.at n=40A034291
- Number of nonempty subsets of {1,2,...,n} in which exactly 2/3 of the elements are <= sqrt(n).at n=36A048095
- 22-gonal numbers: a(n) = n*(10*n-9).at n=35A051874
- Let Py(n)=A000330(n)=n-th square pyramidal number. Consider all integer triples (i,j,k), j >= k>0, with Py(i)=Py(j)+Py(k), ordered by increasing i; sequence gives i values.at n=43A053719
- Number of n-celled polyominoes without holes, symmetric about axis 2.at n=35A056880
- Smallest triangular numbers that contain the digits of n anywhere in their middle.at n=19A062829
- a(n) = the least integer that is polygonal in exactly n ways.at n=7A063778
- Add column entries of the table with rows (1,2,0,0...), (0,3,4,5,0,0...), (0,0,6,7,8,9,0,0...), (0,0,0,10,11,12,13,14,0,0...), ...at n=41A064694
- Composite numbers k with no prime factor among (2, 3) (cf. A038509) and such that phi(k) < 2*k/3.at n=35A069043
- Products of members of pairs in A075333.at n=26A075337
- Triangular numbers which are 4-almost primes.at n=43A076578
- Triangular numbers whose external digits form a triangular number. Or triangular number whose MSD and LSD form a triangular number.at n=47A077367
- a(n) = n*(n+2)*(n-2)/3.at n=31A077415
- Sort the digits of these triangular numbers into descending order and drop zeros to get primes.at n=19A082923