6658
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 25
- Digital Root
- 7
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 9990
- Proper Divisor Sum (Aliquot Sum)
- 3332
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Highly Composite
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 3328
- Möbius Function
- 1
- Radical
- 6658
- 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
- 93
- 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
- yes
- Odd
- no
Appears in sequences
- Cubes written in base 9.at n=16A004639
- Number of nonzero elements in the character table of the symmetric group S_n.at n=12A006908
- a(0) = 1, a(n) = 26*n^2 + 2 for n>0.at n=16A010016
- Numbers k such that the continued fraction for sqrt(k) has even period and if the last term of the periodic part is deleted the central term is 80.at n=16A031578
- Numbers having three 1's in base 9.at n=40A043459
- Numbers whose base-4 representation contains exactly three 0's and three 2's.at n=26A045055
- Number of ways to tile a 5 X 2n room with 1x2 Tatami mats. At most 3 Tatami mats may meet at a point.at n=31A068924
- a(n) = 2^n + 3^n + 9^n.at n=4A074531
- Number of partitions of n with at most two even parts.at n=37A096778
- Triangle read by rows: T(n,k) is the number of k-matchings of the corona L'(n) of the ladder graph L(n)=P_2 X P_n. and the complete graph K(1); in other words, L'(n) is the graph constructed from L(n) by adding for each vertex v a new vertex v' and the edge vv'.at n=40A102435
- Triangle read by rows: T(n,k) is the number of k-matchings of the corona L'(n) of the ladder graph L(n)=P_2 X P_n. and the complete graph K(1); in other words, L'(n) is the graph constructed from L(n) by adding for each vertex v a new vertex v' and the edge vv'.at n=44A102435
- A characteristic triangle for the Euler totient function (A000010).at n=51A110032
- Generalized Mancala solitaire (A002491); to get n-th term, start with n and successively round up to next 11 multiples of n-1, n-2, ..., 1, for n>=1.at n=35A113748
- Numbers with composite sum of digits and prime sum of cubes of digits.at n=27A121642
- a(n) = 1 + 1*n + 1*n*2 + 1*n*2*(n-1) + 1*n*2*(n-1)*3 + 1*n*2*(n-1)*3*(n-2) + ... + n!.at n=7A123636
- Sum of all n-digit Cullen numbers.at n=3A131700
- a(n) = prime(prime(A028815(n) - 1) - 1) - 1.at n=35A141136
- Number of binary strings of length n with no substrings equal to 0001 or 0100.at n=15A164394
- Numbers congruent to 2 in the structure of A211000.at n=23A211001
- Central coefficients of triangle A096815.at n=10A212421