3221
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 8
- Digital Root
- 8
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 3222
- 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
- 3220
- Möbius Function
- -1
- Radical
- 3221
- 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
- 22
- 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
- 456
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Primes p such that the multiplicative order of 2 modulo p is (p-1)/5.at n=8A001135
- Squares written in base 8.at n=40A002441
- Numbers that are the sum of 4 positive 5th powers.at n=36A003349
- Fibonacci numbers written in base 4.at n=13A004687
- Coordination sequence T4 for Zeolite Code -PAR.at n=40A009858
- Numbers k such that the continued fraction for sqrt(k) has period 17.at n=19A020356
- a(n) = least m such that if r and s in {1/2, 1/4, 1/6, ..., 1/2n} satisfy r < s, then r < k/m < (k+2)/m < s for some integer k.at n=24A024842
- a(n) = least m such that if r and s in {1/1, 1/2, 1/3, ..., 1/n} satisfy r < s, then r < k/m < (k+3)/m < s for some integer k.at n=29A024843
- a(n) = Sum_{k=1..n} k*[ (n/k)*[ (n/k)*[ n/k ] ] ].at n=12A024933
- Primes with digits in nonincreasing order.at n=51A028867
- Primes of form x^2+65*y^2.at n=20A033241
- Primes of form x^2+77*y^2.at n=19A033249
- Write 1,2,... in a clockwise spiral; sequence gives numbers on positive x axis.at n=28A033951
- Number of partitions of n into parts 3k or 3k+2.at n=47A035361
- Number of partitions of n such that cn(3,5) < cn(0,5) = cn(1,5) <= cn(2,5) = cn(4,5).at n=67A036875
- Primes p such that x^23 = 2 has no solution mod p.at n=21A040984
- Denominators of continued fraction convergents to sqrt(712).at n=7A042371
- Numbers k such that the string 6,8 occurs in the base 9 representation of k but not of k-1.at n=43A044313
- Numbers n such that string 2,1 occurs in the base 10 representation of n but not of n-1.at n=36A044353
- Numbers n such that string 2,1 occurs in the base 10 representation of n but not of n+1.at n=36A044734