9451
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 19
- Digital Root
- 1
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 10192
- Proper Divisor Sum (Aliquot Sum)
- 741
- 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
- 8712
- Möbius Function
- 1
- Radical
- 9451
- 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
- 153
- 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
- Erroneous version of A002572.at n=18A001180
- Number of partitions of 1 into n powers of 1/2; or (according to one definition of "binary") the number of binary rooted trees.at n=18A002572
- Numbers k such that the continued fraction for sqrt(k) has period 88.at n=20A020427
- Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 44 ones.at n=34A031812
- Numbers whose base-5 representation contains exactly three 0's and two 3's.at n=34A045201
- a(n) = smallest number > a(n-1) such that a(1)*a(2)*...*a(n) + 1 and a(1)*a(2)*...*a(n) - 1 are primes.at n=27A051956
- Number of triangulations of the cyclic polytope C(n, n-4).at n=19A066342
- a(n) = (3*n+4)*2^(n-3)-(2*n-1).at n=9A066374
- Centered 15-gonal numbers: a(n) = (15*n^2 - 15*n + 2)/2.at n=35A069128
- Vertical of triangular spiral in A051682.at n=45A081271
- Start with Pascal's triangle; form a rhombus by sliding down n steps from top on both sides then sliding down inwards to complete the rhombus and then deleting the inner numbers; a(n) = sum of entries on perimeter of rhombus.at n=7A081495
- Diagonal sums of number array A082105.at n=12A082107
- Counterexamples to the conjecture that an even, prime-indexed triangular plus 1 equals a prime or that an odd, prime-indexed triangular minus 2 equals a prime.at n=10A097785
- Numbers n such that concatenation of n and its 10's complement is a palindrome.at n=6A109625
- Numbers k such that concatenation of k and its 10's complement is a palindromic prime.at n=3A109627
- a(n) = n*(n^2 + 2*n - 1)/2.at n=25A127736
- Numbers that appear exactly five times in A101402. (Also indices of fives in A101403.).at n=6A129117
- a(n) = 225*n + 1.at n=41A158229
- a(n) = 42*n^2 + 1.at n=15A158604
- a(n) = 15n^2 + 3n + 1.at n=24A165806