9521
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 17
- Digital Root
- 8
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 9522
- Proper Divisor Sum (Aliquot Sum)
- 1
- 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
- 9520
- Möbius Function
- -1
- Radical
- 9521
- Omega Function (Ω)
- 1
- Little Omega Function (ω)
- 1
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
- 34
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- yes
- Composite Number
- no
- Semiprime
- no
- Squarefree Number
- yes
- Prime Power
- yes
- Prime Factorization
- no
- Twin Prime
- no
- Mersenne Prime
- no
- Sophie Germain Prime
- no
- Safe Prime
- no
- Powerful Number
- no
- Achilles Number
- no
- Prime Index
- 1179
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- a(n) = floor((7*2^(n+1)-9*n-10)/3).at n=11A005262
- a(n) is the sum over all floor(k^3/n), k=0 to n inclusive.at n=32A014818
- Numbers k such that the continued fraction for sqrt(k) has period 81.at n=5A020420
- Expansion of g.f. 1/((1-6*x)*(1-11*x)*(1-12*x)).at n=3A020766
- Greatest prime divisor of prime(n)*prime(n-1) - 1.at n=32A023517
- Least odd prime divisor of prime(n)*prime(n-1) - 1, or 1 if prime(n)*prime(n-1) - 1 is a power of 2.at n=33A023519
- The 20 primes inside the 4 X 4 matrix with all the rows, columns and major diagonals being reversible non-palindromic and distinct primes (the smallest prime-magical square): [ 1933, 1283, 9551, 3719 ].at n=18A032530
- Primes with distinct digits in descending order.at n=48A052014
- McKay-Thompson series of class 42a for Monster.at n=48A058675
- Numbers k such that 41^k - 40^k is prime.at n=6A062607
- Primes of the form 2*n^2 - 1.at n=34A066436
- Centered 16-gonal numbers.at n=34A069129
- Smallest prime equal to the sum of 2n+1 consecutive primes.at n=32A070934
- Primes which are the sum of the first k odd primes for some k.at n=7A071151
- Smallest odd prime that is the sum of 2n+1 consecutive primes.at n=32A082244
- Primes p having exactly one partition into distinct divisors of p+1.at n=30A085499
- Primes equal to a product of twin primes minus 1 divided by 2.at n=6A086870
- Primes p such that p^2+p-1 and p^2+p+1 are twin primes.at n=26A088483
- Primes in which the unit place digit is 1 and the k-th most significant digit is prime (2,3,5,7) if k is prime else is composite (4,6,8,9,0).at n=23A089704
- Least initial value for a Euclid/Mullin sequence whose 3rd term (= least prime divisor of 1+2p) equals the n-th prime. prime(1)=2 is never a third term, so offset=2.at n=31A094464