1229
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 14
- Digital Root
- 5
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 1230
- 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
- 1228
- Möbius Function
- -1
- Radical
- 1229
- 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
- 39
- 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
- yes
- Mersenne Prime
- no
- Sophie Germain Prime
- yes
- Safe Prime
- no
- Powerful Number
- no
- Achilles Number
- no
- Prime Index
- 201
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Primes p == 3, 9, 11 (mod 20) such that 2p+1 is also prime.at n=21A000355
- Number of disconnected graphs with n nodes.at n=8A000719
- Lesser of twin primes.at n=41A001359
- Divisible only by primes congruent to 4 mod 7.at n=38A004622
- a(n) = floor(n*phi^10), where phi is the golden ratio, A001622.at n=10A004925
- Sophie Germain primes p: 2p+1 is also prime.at n=43A005384
- Primes of form k^2 + 4.at n=9A005473
- Number of n-covers of an unlabeled 3-set.at n=7A005745
- Number of carbon trees with n carbon atoms.at n=9A005962
- Discriminants of totally real cubic fields.at n=31A006832
- Number of primes < 10^n.at n=4A006880
- Primes with both 10 and -10 as primitive root.at n=39A007349
- Smallest prime > n^2.at n=34A007491
- Numbers n such that n, 2n+1, and 4n+3 all prime.at n=11A007700
- Coordination sequence T2 for Zeolite Code BOG.at n=25A008050
- Coordination sequence T4 for Zeolite Code BRE.at n=23A008061
- Least m such that if a/b < c/d are Farey fractions of order n then there exists k such that a/b < k/m < c/d, k/m reduced.at n=40A009571
- Coordination sequence T4 for Zeolite Code -PAR.at n=25A009858
- Numbers k such that the continued fraction for sqrt(k) has period 5.at n=34A010337
- Least d for which the number with continued fraction [n,n,n,n...] is in Q(sqrt(d)).at n=34A013946