4915
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 19
- Digital Root
- 1
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 5904
- Proper Divisor Sum (Aliquot Sum)
- 989
- 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
- 3928
- Möbius Function
- 1
- Radical
- 4915
- 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
- 134
- 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
- a(n) = ceiling(exp((n-1)/2)).at n=18A005181
- a(0) = 1, a(n) = 17*n^2 + 2 for n>0.at n=17A010007
- a(1) = a(2) = 1, a(2n + 1) = 2*a(2n) and a(2n) = 2*a(2n - 1) + (-1)^n.at n=13A016029
- Numbers k such that the continued fraction for sqrt(k) has period 66.at n=14A020405
- Number of 1's in n-th term of A007651.at n=32A022466
- Least m such that if r and s in {1/1, 1/3, 1/6,..., 1/C(n+1,2)} satisfy r < s, then r < k/m < s for some integer k.at n=29A024826
- a(n) = s(n+3)/6, where s is A024953.at n=10A024954
- Diagonal sum of left justified array T given by A027082.at n=23A027100
- 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 13.at n=42A031511
- Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 30 ones.at n=37A031798
- Numbers whose set of base-16 digits is {1,3}.at n=21A032923
- a(n) = (n-1)*(n-2)*(n-3) + n.at n=18A034324
- Number of partitions satisfying cn(0,5) < cn(1,5) + cn(4,5).at n=29A039842
- Numbers having three 6's in base 9.at n=19A043479
- Numbers whose base-4 representation contains exactly three 0's and three 3's.at n=15A045079
- Integer part of square root of n-th Fibonacci number.at n=37A061287
- Centered 13-gonal numbers.at n=27A069126
- Centered 14-gonal numbers.at n=26A069127
- Expansion of 1/(1-x+2*x^3).at n=25A077950
- Expansion of (1-x)/(1+2*x+x^2+2*x^3).at n=12A078066