12741
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 15
- Digital Root
- 6
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 17664
- Proper Divisor Sum (Aliquot Sum)
- 4923
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 8160
- Möbius Function
- -1
- Radical
- 12741
- Omega Function (Ω)
- 3
- Little Omega Function (ω)
- 3
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
- 32
- 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
- Least k such that first k terms of A022300 contain n more 2's than 1's.at n=18A025515
- McKay-Thompson series of class 31A for Monster.at n=36A058628
- Ulam's spiral (SSE spoke).at n=28A143839
- Records in A153004.at n=46A153838
- G.f.: Sum_{n>=0} a(n)*x^n/n!^2 = Product_{n>=1} (1 + x^n/n!^2).at n=7A183229
- Triangle read by rows: T(n,k) is the number of permutations of {1,2,...,n} having k increasing even cycles (0<=k<=n). A cycle (b(1), b(2), ...) is said to be increasing if, when written with its smallest element in the first position, it satisfies b(1)<b(2)<b(3)<... . A cycle is said to be even if it has an even number of entries. For example, the permutation (18)(2347)(569) has 2 increasing even cycles.at n=21A186764
- Principal diagonal of the convolution array A213783.at n=40A213759
- Number of compositions of n where the difference between largest and smallest parts equals 5 and adjacent parts are unequal.at n=15A214274
- Number of n X 2 0,1 arrays indicating 2 X 2 subblocks of some larger (n+1) X 3 binary array having a sum of three or less, with rows and columns of the latter in lexicographically nondecreasing order.at n=22A227265
- The Wiener index of the graph obtained by applying Mycielski's construction to the crown graph G(n) (n>=3).at n=28A228598
- Position of [n, n-1, ..., 2, 1] in Mathematica-ordered list of partitions of n(n+1)/2.at n=8A238639
- Composites whose prime factorization in base 6 is an anagram of the number in base 6.at n=40A260050
- Central terms of triangle in A075383.at n=46A263896
- Total number of parts of the second sort in all partitions of n into two sorts of parts.at n=10A278464
- Number of balanced reduced multisystems whose atoms cover an initial interval of positive integers with multiplicities equal to the prime indices of n.at n=33A318846
- Numbers k such that 483*2^k+1 is prime.at n=32A320339
- Number of partitions of n into an odd number of relatively prime parts.at n=37A339398
- a(n) = Sum_{k=1..n} k * rad(k).at n=36A350996
- a(n) = Sum_{k=0..floor(n/3)} binomial(3*n-3*k-1,n-3*k).at n=6A371770