4995
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 27
- Digital Root
- 9
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 16
- Divisor Sum
- 9120
- Proper Divisor Sum (Aliquot Sum)
- 4125
- 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
- 2592
- Möbius Function
- 0
- Radical
- 555
- Omega Function (Ω)
- 5
- Little Omega Function (ω)
- 3
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
- yes
- Harshad Number
- yes
- Narcissistic Number
- no
- Collatz Steps
- 90
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- no
- Squarefree Number
- no
- 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
- Number of trees with n nodes, 2 of which are labeled.at n=8A000243
- Heptagonal numbers (or 7-gonal numbers): n*(5*n-3)/2.at n=45A000566
- Coordination sequence T12 for Zeolite Code MFI.at n=45A008164
- Odd heptagonal numbers (A000566).at n=22A014637
- Expansion of e.g.f. theta_3^(-1/2).at n=6A015680
- Numbers k such that the period of the continued fraction for sqrt(k) contains exactly seven 1's.at n=23A020443
- a(n) = n*(n^3 - 1)/2.at n=8A027482
- a(n) = (2*n + 1)*(5*n + 1).at n=22A033571
- Triangle of number of node labeled trees by number of nodes and number of labels.at n=47A034800
- Numbers congruent to 2,3,6,11 mod 12 missing from A042944 (conjectured to be finite).at n=27A042945
- Number of ways to label points of an n X n grid with 3 colors, up to rotational symmetry.at n=3A047938
- T(n,6), array T as in A050186; a count of aperiodic binary words.at n=9A050191
- T(2n+3,n), array T as in A050186; a count of aperiodic binary words.at n=6A051196
- Numbers of the form k*(k^3 +- 1)/2.at n=18A057590
- Numbers k such that the Lucas Aurifeuillian primitive part B of Lucas(k) is prime.at n=44A061443
- Numbers k such that (k + R(k)) / (k - R(k)) = +-11 where R(k) is the digit reversal of k (A004086).at n=5A062390
- a(n) = C(n+6, 6) - n - 1.at n=9A062989
- Numbers k such that sigma_k(k)/k is an integer, where sigma_k(k) is the sum of the k-th powers of the divisors of k (A023887).at n=35A067313
- 1/n has period 3 in base 10.at n=55A069105
- Smallest multiple of 5 with digit sum n.at n=26A069534