2609
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 17
- Digital Root
- 8
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 2610
- Proper Divisor Sum (Aliquot Sum)
- 1
- 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
- 2608
- Möbius Function
- -1
- Radical
- 2609
- Omega Function (Ω)
- 1
- Little Omega Function (ω)
- 1
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
- 53
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- yes
- Composite Number
- no
- Semiprime
- no
- Squarefree Number
- yes
- Prime Power
- yes
- Prime Factorization
- no
- Twin Prime
- no
- Mersenne Prime
- no
- Sophie Germain Prime
- no
- Safe Prime
- no
- Powerful Number
- no
- Achilles Number
- no
- Prime Index
- 379
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Smallest nonnegative number that is the sum of 3 squares in exactly n ways.at n=21A000437
- Smallest number that is the sum of 3 squares in at least n ways.at n=21A000451
- Smallest number that is the sum of 3 squares in at least n ways.at n=20A000451
- Smallest k such that the product of q/(q-1) over the primes from prime(n) to prime(n+k-1) is greater than 2.at n=34A001276
- Number of simple perfect squared rectangles of order n up to symmetry.at n=14A002839
- Number of pairings {(b(1), c(1)), (b(2), c(2)), ..., (b(n), c(n))} of the first 2n positive integers satisfying b(i) < c(i) and such that the 2n numbers c(i)+b(i) and c(i)-b(i) are all distinct.at n=8A002968
- Number of partitions of n into Fibonacci parts (with a single type of 1).at n=46A003107
- a(n) = 3*n^2 + 3*n - 1.at n=29A004538
- From relations between Siegel theta series.at n=29A006476
- Oscillates under partition transform.at n=45A007212
- Coordination sequence T1 for Zeolite Code KFI.at n=39A008123
- Coordination sequence T1 for Zeolite Code PHI.at n=37A008227
- Apply partial sum operator thrice to Stern's sequence.at n=10A014173
- Twelve iterations of Reverse and Add are needed to reach a palindrome.at n=6A015993
- Numbers k such that the continued fraction for sqrt(k) has period 37.at n=5A020376
- Primes that remain prime through 2 iterations of the function f(x) = 2x + 9.at n=47A023245
- Primes that remain prime through 2 iterations of function f(x) = 8x + 7.at n=23A023263
- Primes that remain prime through 2 iterations of function f(x) = 10x + 9.at n=46A023270
- Integer part of ((4th elementary symmetric function of 2,3,...,n+4)/(2+3+...+n+4)).at n=5A024179
- a(n) = s(1)s(n) + s(2)s(n-1) + ... + s(k)s(n-k+1), where k = [ n/2 ], s = A000201 (lower Wythoff sequence).at n=21A025118