2655
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
- 12
- Divisor Sum
- 4680
- Proper Divisor Sum (Aliquot Sum)
- 2025
- 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
- 1392
- Möbius Function
- 0
- Radical
- 885
- 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
- 53
- 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
- Coefficients in expansion of e as Sum_{n>=1} a(n)/(n*n!*(n+1)!), as found by greedy algorithm.at n=51A011189
- Number of partitions of n into 7 unordered relatively prime parts.at n=33A023027
- s(1)t(n) + s(2)t(n-1) + ... + s(k)t(n+1-k), where k = [ (n+1)/2 ], s = A023532, t = (1, p(1), p(2), ...).at n=46A024369
- a(n) = [ 2nd elementary symmetric function of {sqrt(k+1)} ], k = 1,2,...,n.at n=20A025219
- a(n) = Sum_{k=0..floor(n/2)} T(n,k), T given by A026758.at n=11A026766
- Sums of five consecutive squares: a(n) = n^2 + (n+1)^2 + (n+2)^2 + (n+3)^2 + (n+4)^2.at n=21A027578
- a(n) = n^2 + n + 3.at n=51A027688
- Every run of digits of n in base 4 has length 2.at n=26A033002
- Numerators of continued fraction convergents to sqrt(55).at n=5A041094
- Numerators of continued fraction convergents to sqrt(220).at n=5A041410
- Denominators of continued fraction convergents to sqrt(685).at n=7A042317
- Numbers n such that string 5,7 occurs in the base 9 representation of n but not of n-1.at n=36A044303
- Numbers n such that string 7,0 occurs in the base 9 representation of n but not of n-1.at n=35A044314
- Numbers n such that string 5,5 occurs in the base 10 representation of n but not of n-1.at n=26A044387
- Numbers n such that string 7,0 occurs in the base 9 representation of n but not of n+1.at n=35A044695
- Numbers n such that string 5,5 occurs in the base 10 representation of n but not of n+1.at n=26A044768
- Starting positions of strings of 2 8's in the decimal expansion of Pi.at n=24A050263
- Let R(i,j) be the rectangle with antidiagonals 1; 2,3; 4,5,6; ...; the n-th Fibonacci number is in antidiagonal a(n).at n=32A057042
- Penrice Christmas gift numbers, Card-matching numbers (Dinner-Diner matching numbers): Triangle T(n,k) = number of ways to get k matches for a deck with n cards, 2 of each kind.at n=44A059056
- Numerator of 1/49 - 1/n^2.at n=45A061047