4444
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 16
- Digital Root
- 7
- Palindromic Number
- yes
- Repdigit
- yes
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 12
- Divisor Sum
- 8568
- Proper Divisor Sum (Aliquot Sum)
- 4124
- 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
- 2000
- Möbius Function
- 0
- Radical
- 2222
- Omega Function (Ω)
- 4
- 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
- no
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 33
- 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
- yes
- Odd
- no
Appears in sequences
- Concatenate n n times.at n=3A000461
- Trajectory of 1 under map x->x + (x-with-digits-reversed).at n=10A001127
- a(n) = 4*(10^n - 1)/9.at n=4A002278
- Squares written in base 7.at n=39A002440
- Representation degeneracies for Ramond strings.at n=13A005306
- Coordination sequence T5 for Zeolite Code VET.at n=41A009906
- Repdigit numbers, or numbers whose digits are all equal.at n=31A010785
- Numbers > 9 with all digits the same.at n=21A014181
- Coordination sequence T3 for Zeolite Code CZP.at n=43A019458
- Number of partitions of 1/n into 4 reciprocals of positive integers.at n=10A020327
- Doublets: base-10 representation is the juxtaposition of two identical strings.at n=43A020338
- Convolution of odd numbers and A000201.at n=19A023658
- a(n) = (d(n) - r(n))/5, where d = A026037 and r is the periodic sequence with fundamental period (1,2,0,2,0).at n=38A026039
- Numbers whose set of base-10 digits is {1,4}.at n=29A032822
- Numbers with digits 3 and 4 only.at n=29A032834
- Numbers whose maximal base-10 run length is 4.at n=3A033285
- Trajectory of 25 under map x->x + (x-with-digits-reversed).at n=6A033658
- Trajectory of 59 under map x->x + (x-with-digits-reversed).at n=5A033671
- Number of pairs {i,j}, i>1, j>1, such that ij < n^2.at n=38A037048
- Numbers whose sum of reciprocals of digits is the reciprocal of an integer.at n=44A037264