2399
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 23
- Digital Root
- 5
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 4
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 2400
- 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
- 2398
- Möbius Function
- -1
- Radical
- 2399
- 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
- 71
- 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
- 357
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Smallest prime == 7 (mod 8) where Q(sqrt(-p)) has class number 2n+1.at n=29A002146
- Lucasian primes: p == 3 (mod 4) with 2*p+1 prime.at n=36A002515
- a(1) = 3; for n>0, a(n+1) = a(n) + floor((a(n)-1)/2).at n=18A003312
- Primes of form 2n^2 - 2n + 19.at n=28A007639
- a(n) = n^2 - 2.at n=48A008865
- Expansion of 1/(1-x^2-x^3-x^4-x^5-x^6-x^7-x^8-x^9).at n=19A013986
- Ordered sequence of distinct terms of the form floor(x^i * floor(x^j)), i,j >= 0, where x = sqrt(7).at n=23A022771
- Primes that remain prime through 2 iterations of function f(x) = 6x + 7.at n=35A023258
- Primes that remain prime through 2 iterations of function f(x) = 10x + 3.at n=46A023269
- Primes that remain prime through 3 iterations of function f(x) = 10x + 3.at n=15A023300
- Right-truncatable primes: every prefix is prime.at n=30A024770
- 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+4)/m < s for some integer k.at n=22A024846
- Numbers whose least quadratic nonresidue (A020649) is 11.at n=13A025024
- Coordination sequence T1 for Zeolite Code CGS.at n=36A027365
- Primes of the form k^2 - 2.at n=16A028871
- Squarefree n such that Q(sqrt(n)) has class number 5.at n=18A029705
- a(n) = prime(9*n - 3).at n=39A031390
- a(n) = prime(10*n-3).at n=35A031391
- Numbers k such that the continued fraction for sqrt(k) has even period and if the last term of the periodic part is deleted the central term is 47.at n=17A031545
- Lower prime of a difference of 12 between consecutive primes.at n=22A031930