4851
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 18
- Digital Root
- 9
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 18
- Divisor Sum
- 8892
- Proper Divisor Sum (Aliquot Sum)
- 4041
- 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
- 2520
- Möbius Function
- 0
- Radical
- 231
- 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
- yes
- 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
- 165
- 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 connected topologies on n labeled points.at n=5A001929
- Pentagonal pyramidal numbers: a(n) = n^2*(n+1)/2.at n=21A002411
- Mian-Chowla sequence (a B_2 sequence): a(1) = 1; for n>1, a(n) = smallest number > a(n-1) such that the pairwise sums of elements are all distinct.at n=49A005282
- Number of motifs in triangular window of side n.at n=5A007017
- Molien series for 6-dimensional complex reflection group 4.U_4 (3) of order 2^9 .3^7 .5.7.at n=44A008581
- Three-fold convolution of primes with themselves.at n=7A014343
- Odd triangular numbers.at n=49A014493
- Odd pentagonal pyramidal numbers.at n=5A015223
- Binomial coefficients C(n,97).at n=2A017761
- Binomial coefficients C(99,n).at n=2A017815
- Smallest triangular number that begins with n.at n=47A018855
- Expansion of 1/((1-x)*(1-3*x)*(1-4*x)*(1-5*x)).at n=4A021344
- a(n) = T(2n,n), where T is the array defined in A026105.at n=6A026112
- T(n,[ n/2 ]), where T is the array defined in A026105.at n=12A026117
- a(n) = T(n,0) + T(n,1) + ... + T(n,[ n/2 ]), T given by A026659.at n=12A026667
- Sum{T(n-k,k)}, 0<=k<=[ n/2 ], T given by A026681.at n=16A026691
- a(n) = (1/2)*floor(n/2)*floor((n-1)/2)*floor((n-2)/2).at n=44A028724
- (prime(n)-1)(prime(n)-3)/8.at n=44A030005
- Lucky numbers that are decimal concatenations of n with n + 3.at n=6A032653
- a(n) = (2*n-1)*(4*n-1).at n=25A033567