1223
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
- 1224
- 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
- 1222
- Möbius Function
- -1
- Radical
- 1223
- 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
- 132
- 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
- yes
- Safe Prime
- no
- Powerful Number
- no
- Achilles Number
- no
- Prime Index
- 200
- 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=20A000355
- Primes with 5 as smallest primitive root.at n=31A001124
- Lucasian primes: p == 3 (mod 4) with 2*p+1 prime.at n=22A002515
- Numbers k such that (k^2 + k + 1)/19 is prime.at n=35A002643
- Number of partially achiral planted trees with n nodes.at n=15A003237
- Symmetries in unrooted 4-trees on n+1 vertices.at n=10A003616
- Primes written in base 4.at n=27A004678
- Numbers k such that 4!*(2k-5)!/(k!*(k-1)!) is an integer.at n=9A004784
- 5!(2n-6)!/n!(n-1)! is an integer.at n=11A004785
- Sophie Germain primes p: 2p+1 is also prime.at n=42A005384
- Smallest number of complexity n: smallest number requiring n 1's to build using + and *.at n=23A005520
- Minimal number of moves for the cyclic variant of the Towers of Hanoi for 3 pegs and n disks, with the final peg two steps away.at n=7A005666
- Prime self (or Colombian) numbers: primes not expressible as the sum of an integer and its digit sum.at n=24A006378
- Numbers k such that k-6, k, and k+6 are primes.at n=32A006489
- Balanced primes (of order one): primes which are the average of the previous prime and the following prime.at n=18A006562
- Coordination sequence T1 for Zeolite Code AFO.at n=23A008015
- Coordination sequence T3 for Zeolite Code BOG.at n=25A008051
- Coordination sequence T3 for Zeolite Code NES.at n=22A008207
- Number of 3 X 3 symmetric stochastic matrices under row and column permutations.at n=41A008764
- a(n) = n^2 - 2.at n=34A008865