6221
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
- 2
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 6222
- 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
- 6220
- Möbius Function
- -1
- Radical
- 6221
- 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
- 36
- 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
- 810
- 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=18A001135
- Generalized divisor function. Number of partitions of n with exactly three part sizes.at n=45A002134
- Expansion of e.g.f.: 1/(2-x-exp(x)).at n=5A006155
- [ exp(4/19)*n! ].at n=6A030874
- Numbers k such that 113*2^k+1 is prime.at n=17A032406
- Denominators of continued fraction convergents to sqrt(946).at n=9A042831
- Numbers having four 4's in base 6.at n=20A043388
- Primes with first digit 6.at n=44A045712
- Discriminants of real quadratic fields with class number 1 and related continued fraction period length of 13.at n=21A050962
- McKay-Thompson series of class 28A for Monster.at n=28A058606
- Primes p such that p^5 reversed is also prime.at n=34A059698
- Primes p such that p^7 reversed is also prime.at n=41A059700
- Primes with either no internal digits or all internal digits are 2.at n=45A069677
- Expansion of (1-x)^(-1)/(1+2*x^2+2*x^3).at n=20A077895
- Square number array T(n,k) = (k*(k+2)^n+1)/(k+1) read by antidiagonals.at n=50A083064
- 5th row of number array A083064.at n=5A083066
- First superdiagonal of number array A083064.at n=4A083070
- a(n) = (A085249(n) - 1)/6.at n=14A088349
- Numbers of the form prime(prime(n)+1), with n satisfying prime(n)+2 = prime(n+1).at n=30A088985
- 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=12A089704