2987
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 26
- Digital Root
- 8
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 3120
- Proper Divisor Sum (Aliquot Sum)
- 133
- 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
- 2856
- Möbius Function
- 1
- Radical
- 2987
- Omega Function (Ω)
- 2
- Little Omega Function (ω)
- 2
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
- 48
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- yes
- Squarefree Number
- yes
- Prime Power
- no
- Prime Factorization
- no
- Twin Prime
- no
- Mersenne Prime
- no
- Sophie Germain Prime
- no
- Safe Prime
- no
- Powerful Number
- no
- Achilles Number
- no
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- First occurrence of n consecutive numbers that take same number of steps to reach 1 in 3x+1 problem.at n=13A000546
- Numbers that are the sum of 12 positive 6th powers.at n=47A003368
- Number of factorization patterns of polynomials of degree n over F_2.at n=20A006167
- Coordination sequence T3 for Zeolite Code EUO.at n=34A008098
- Expansion of e.g.f. arctanh(cos(x)*log(x+1)).at n=7A012471
- Seven iterations of Reverse and Add are needed to reach a palindrome.at n=38A015986
- Expansion of 1/(1-x^4-x^5-x^6-x^7-x^8-x^9-x^10-x^11-x^12-x^13-x^14).at n=31A017836
- Define the generalized Pisot sequence T(a(0),a(1)) by: a(n+2) is the greatest integer such that a(n+2)/a(n+1) < a(n+1)/a(n). This is T(2,6).at n=7A018915
- a(n) = 3*a(n-1) - a(n-2) + 2*a(n-3) - 2*a(n-4).at n=7A019487
- a(n) is the concatenation of n and 3n.at n=28A019551
- a(n) is the position of square of n-th prime among the powers of primes (A000961).at n=37A024624
- Positions of squares among the powers of primes (A000961).at n=51A024626
- a(n) = position of n^3 + (n+1)^3 + (n+2)^3 in A024975.at n=20A024980
- a(n) = T(2n-1,n), where T is the array in A026098.at n=26A026102
- Coordination sequence T4 for Zeolite Code SBE.at n=44A033607
- Offsets for the Atkin Partition Congruence theorem.at n=29A036492
- Number of B-trees of order 4 with n leaves.at n=19A037026
- Numbers n such that the string 7,8 occurs in the base 9 representation of n but not of n-1.at n=36A044322
- Numbers n such that string 8,7 occurs in the base 10 representation of n but not of n-1.at n=32A044419
- Numbers n such that string 7,8 occurs in the base 9 representation of n but not of n+1.at n=36A044703