13349
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 20
- Digital Root
- 2
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 15264
- Proper Divisor Sum (Aliquot Sum)
- 1915
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 11436
- Möbius Function
- 1
- Radical
- 13349
- 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
- 68
- 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
- Numbers k such that k divides the (left) concatenation of all numbers <= k written in base 15 (most significant digit on right and removing all least significant zeros before concatenation).at n=13A029532
- a(1)=4, then least semiprime > a(n-1) such that when all in the sequence are concatenated together they form a prime.at n=32A085703
- Derived from the centered polygonal numbers: start with the first triangular number, then the sum of the first square number and the second triangular number, then the sum of first pentagonal number, the second square number and the third triangular number, and so on and so on...at n=21A141534
- Partial sums of A048995.at n=43A174514
- Number of disconnected 4-regular simple graphs on n vertices with girth exactly 3.at n=18A185043
- Triangular array D(n,k) counting disconnected k-regular simple graphs on n vertices with girth exactly 3.at n=76A210703
- Number of (n+2)X(n+2) 0..1 arrays with every 3X3 subblock sum of the two sums of the central row and central column minus the two minimums of the diagonal and antidiagonal nondecreasing horizontally and vertically.at n=1A256947
- Number of (n+2)X(2+2) 0..1 arrays with every 3X3 subblock sum of the two sums of the central row and central column minus the two minimums of the diagonal and antidiagonal nondecreasing horizontally and vertically.at n=1A256948
- T(n,k)=Number of (n+2)X(k+2) 0..1 arrays with every 3X3 subblock sum of the two sums of the central row and central column minus the two minimums of the diagonal and antidiagonal nondecreasing horizontally and vertically.at n=4A256954
- Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 798", based on the 5-celled von Neumann neighborhood.at n=28A273571
- Number of parts in all partitions of n with largest multiplicity nine.at n=28A320379
- Numbers that are the sum of nine fourth powers in nine or more ways.at n=29A345593
- Numbers that are the sum of nine fourth powers in ten or more ways.at n=4A345594
- Numbers that are the sum of nine fourth powers in exactly ten ways.at n=4A345852
- a(n) = Sum_{k=1..n} (-1)^(k+1) * floor(n/(2*k-1))^3.at n=23A350163
- Lesser of 2 successive squarefree semiprimes (k, k+4) sandwiching 3 consecutive nonsquarefree numbers.at n=36A363821
- Semiprimes k such that none of k-2, k-1, k+1, and k+2 is squarefree.at n=41A364010