1123
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 7
- Digital Root
- 7
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 1124
- 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
- 1122
- Möbius Function
- -1
- Radical
- 1123
- 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
- 44
- 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
- 188
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Primes that divide at least one term in every Fibonacci sequence.at n=39A000057
- Expansion of e.g.f. exp(x)*(1 + tan(x))/(1 - tan(x)).at n=5A000834
- Primes p of the form 3k+1 such that Sum_{x=1..p} cos(2*Pi*x^3/p) > sqrt(p).at n=48A000921
- Smallest natural number requiring n letters in English.at n=32A001166
- Number of letters in English name for n increases at these numbers.at n=23A001619
- Central polygonal numbers: a(n) = n^2 - n + 1.at n=34A002061
- Primes of form k^2 + k + 1.at n=14A002383
- Expansion of 1 / ((1-x)^2*(1-x^2)*(1-x^3)*(1-x^4)).at n=23A002621
- Numbers that are the sum of 7 positive 5th powers.at n=33A003352
- Start with a(1)=1; to get a(n) replace each i in a(n-1) with 12...i, then append n.at n=2A004073
- Primes written in base 5.at n=37A004679
- Numbers k such that k-6, k, and k+6 are primes.at n=30A006489
- Balanced primes (of order one): primes which are the average of the previous prime and the following prime.at n=16A006562
- Expansion of critical exponent for walks on tetrahedral lattice.at n=6A007180
- Where the prime race among 7k+1, ..., 7k+6 changes leader.at n=9A007354
- Les Marvin sequence: a(n) = F(n) + (n-1)*F(n-1), F() = Fibonacci numbers.at n=11A007502
- Primes == 3 (mod 8).at n=47A007520
- Shifts left when inverse Moebius transform applied twice.at n=25A007557
- Primes of form 2n^2 - 2n + 19.at n=20A007639
- Numbers that contain only 1's, 2's and 3's.at n=44A007932