2887
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 25
- Digital Root
- 7
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 4
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 2888
- 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
- 2886
- Möbius Function
- -1
- Radical
- 2887
- 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
- 128
- 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
- 418
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Primes p of the form 3k+1 such that sum_{x=1..p} cos(2*Pi*x^3/p) < -sqrt(p).at n=40A000923
- Smallest number requiring n chisel strokes for its representation in Roman numerals.at n=28A002964
- Representation degeneracies for boson strings.at n=29A005291
- a(n) = a(n-1) + a(n - 1 - number of even terms so far).at n=32A006336
- Where the prime race among 5k+1, ..., 5k+4 changes leader.at n=22A007353
- Coordination sequence T3 for Zeolite Code AFS and BPH.at n=41A008025
- Coordination sequence T2 for Scapolite.at n=34A008263
- Numbers k such that the continued fraction for sqrt(k) has period 60.at n=8A020399
- a(n)-th squarefree is sum of first k squarefrees for some k.at n=45A020643
- a(n) = T(n, n-1), T given by A026519. Also a(n) = number of integer strings s(0), ..., s(n), counted by T, such that s(n) = 1.at n=10A026521
- a(n) = T(n,n-1), T given by A026552. Also a(n) is the number of integer strings s(0),...,s(n) counted by T, such that s(n)=1.at n=10A026554
- a(n) = Sum_{i=0..n} Sum_{j=0..n} T(i,j), T given by A026780.at n=9A026789
- a(n) = prime(10*n - 2).at n=41A031384
- 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 53.at n=8A031551
- Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 22 ones.at n=33A031790
- Lucky numbers with size of gaps equal to 10 (upper terms).at n=30A031893
- Lucky numbers with size of gaps equal to 12 (lower terms).at n=35A031894
- Upper prime of a difference of 8 between consecutive primes.at n=38A031927
- Lower prime of a difference of 10 between consecutive primes.at n=39A031928
- Numbers whose set of base-13 digits is {1,4}.at n=18A032825