5151
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 12
- Digital Root
- 3
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 7344
- Proper Divisor Sum (Aliquot Sum)
- 2193
- 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
- 3200
- Möbius Function
- -1
- Radical
- 5151
- Omega Function (Ω)
- 3
- 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
- yes
- 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
- 90
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- no
- 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) = floor(n*phi^12), where phi is the golden ratio, A001622.at n=16A004927
- Coordination sequence T5 for Zeolite Code MTW.at n=47A008200
- a(n) = prime(n)*(prime(n+1)-1)/2.at n=25A014303
- a(n) = (2*n+1)*(4*n+1).at n=25A014634
- Triangle of numbers associated with Genocchi numbers.at n=29A014780
- Triangle of numbers associated with Genocchi numbers.at n=31A014780
- Triangle of numbers associated with Genocchi numbers.at n=21A014782
- Triangle of numbers associated with Genocchi numbers.at n=23A014782
- a(n) = binomial coefficient C(n,100).at n=2A017764
- Smallest triangular number that begins with n.at n=50A018855
- Pseudoprimes to base 16.at n=43A020144
- Pseudoprimes to base 52.at n=21A020180
- Strong pseudoprimes to base 52.at n=6A020278
- Numbers k such that the period of the continued fraction for sqrt(k) contains exactly seven 1's.at n=24A020443
- a(n) = least m such that if r and s in {1/2, 1/4, 1/6, ..., 1/(2*n)} satisfy r < s, then r < k/m < (k+3)/m < s for some integer k.at n=26A024845
- Lucky numbers that are concatenations of a number k with itself.at n=4A032650
- a(1) = 1; a(n) is smallest number >= a(n-1) such that the juxtaposition a(1)a(2)...a(n) is a prime.at n=41A033680
- Triangular numbers (A000217) with prime indices.at n=25A034953
- Odd triangular numbers with prime indices.at n=12A034954
- Images of hexamorphic numbers: suppose k-th hexagonal number H(k) (A000384) ends in k; sequence gives positive values of H(k).at n=6A038494