2543
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
- 2
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 2544
- 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
- 2542
- Möbius Function
- -1
- Radical
- 2543
- 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
- 177
- 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
- 372
- 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=35A000355
- Lucasian primes: p == 3 (mod 4) with 2*p+1 prime.at n=38A002515
- Coordination sequence T3 for Zeolite Code AFT.at n=38A008028
- Coordination sequence T2 for Zeolite Code AWW.at n=36A008046
- Coordination sequence T1 for Zeolite Code LTN.at n=35A008140
- Coordination sequence T2 for Zeolite Code RSN.at n=33A009886
- a(0) = 1, a(n) = 21*n^2 + 2 for n>0.at n=11A010011
- Primes that remain prime through 2 iterations of function f(x) = 8x + 3.at n=28A023261
- Primes that remain prime through 3 iterations of function f(x) = 6x + 5.at n=26A023288
- a(n) = s(1)s(n) + s(2)s(n-1) + ... + s(k)s(n+1-k), where k = [ (n+1)/2 ], s = (composite numbers).at n=18A024588
- a(n) = Sum_{k=1..n} floor((n/k)*floor(n/k)).at n=39A024921
- a(n) is the least odd prime p such that the maximum run length of consecutive quadratic residues modulo p is n.at n=13A025046
- Primes with property that when squared all even digits occur together and all odd digits occur together.at n=27A030480
- 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 49.at n=11A031547
- a(n) = prime(9*n - 6).at n=41A031913
- a(n) = prime(10*n-8).at n=37A031919
- Primes of form x^2+31*y^2.at n=56A033221
- Number of partitions of n with equal number of parts congruent to each of 0, 3 and 4 (mod 5).at n=41A035577
- Triangle of coefficients of generating function of 6-ary rooted trees of height at most n.at n=70A036608
- Number of 6-ary rooted trees with n nodes and height at most 4.at n=15A036621