9101
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 11
- Digital Root
- 2
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 9600
- Proper Divisor Sum (Aliquot Sum)
- 499
- 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
- 8604
- Möbius Function
- 1
- Radical
- 9101
- 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
- 21
- 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
- a(n) = (n + 3)*(n^2 + 6*n + 2)/6.at n=35A005286
- Decimal part of n-th root of a(n) starts with digit 2.at n=48A034079
- Composite numbers whose divisors (except 1) all contain the digit 9.at n=12A062680
- Nested floor product of n and fractions (k+1)/k for all k>0 (mod 3), divided by 3.at n=40A073360
- a(n) = n + floor(Sum_{k<n} a(k)/2) with a(0)=0.at n=21A079719
- Representative lunar primes.at n=30A088574
- Natural numbers written out with their digits grouped in sets of four (leading zeros omitted).at n=2A091332
- Numbers k such that k and k^2 use only the digits 0, 1, 2, 8 and 9.at n=38A136835
- Numbers k that are multiples of the reversal of k-1.at n=8A160945
- Number of reduced words of length n in the Weyl group A_37.at n=3A161650
- Triangle read by rows: T(n,k) = value of the string of length k beginning at position n in the concatenation of natural numbers in decimal representation, 1<=k<=n.at n=39A162711
- a(n) = 6*a(n-1) - a(n-2) + 12 with n>1, a(0)=-1, a(1)=5.at n=5A182191
- a(n) is the least number not occurring earlier such that neighboring digits sum to 1 or 10.at n=15A182396
- Numbers n such that m=(n^2+1)/2, p=(m^2+1)/2 and q=(p^2+1)/2 are all prime.at n=7A188546
- a(n) = Sum_{k=1..n} lcm(k,k')/gcd(k,k'), where n' is arithmetic derivative of n.at n=48A190120
- Put the natural numbers together without spaces and read them four at a time advancing one space each time.at n=8A193492
- Centered 28-gonal numbers.at n=25A195314
- Odd numbers producing 4 odd numbers in the Collatz iteration.at n=23A198587
- Number of (n+1)X(n+1) -9..9 symmetric matrices with every 2X2 subblock having sum zero and one or three distinct values.at n=6A211551
- Number of Dyck n-paths all of whose ascents have lengths equal to 1 (mod 5).at n=15A212385