2765
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 20
- Digital Root
- 2
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 3840
- Proper Divisor Sum (Aliquot Sum)
- 1075
- 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
- 1872
- Möbius Function
- -1
- Radical
- 2765
- 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
- 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
- 128
- 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
- Construct a triangle as in A036262. Sequence is one less than the position of the first number larger than 2 in the n-th row (n-th difference).at n=44A000232
- Coordination sequence T2 for Zeolite Code EPI.at n=33A008091
- Coordination sequence T1 for Zeolite Code YUG.at n=34A008247
- Coordination sequence T3 for Zeolite Code -CLO.at n=46A009852
- Coordination sequence T1 for Zeolite Code -PAR.at n=37A009855
- Coordination sequence T5 for Zeolite Code DFO.at n=40A009879
- Pseudoprimes to base 78.at n=15A020206
- a(n) = s(1)*s(n) + s(2)*s(n-1) + ... + s(k)*s(n+1-k), where k = floor((n+1)/2), s = (natural numbers >= 3).at n=26A024312
- Near Cullen numbers: k such that (k+1)*2^k + 1 is prime.at n=19A029544
- Numbers k such that 53*2^k+1 is prime.at n=13A032376
- Coordination sequence T3 for Zeolite Code SBT.at n=42A033614
- a(n+1) = a(n) + sum of squares of digits of a(n).at n=40A033936
- Position of first term > 2 in n-th row of Gilbreath array shown in A036262.at n=46A036277
- Partial sums of A000009 (partitions into distinct parts).at n=32A036469
- Number of partitions of n such that cn(0,5) = cn(1,5) < cn(2,5) = cn(4,5) <= cn(3,5).at n=61A036870
- Gaps of 2 in sequence A038593 (upper terms).at n=7A038644
- Numbers that are divisible by 5 and are the difference between two (different positive) cubes in at least one way.at n=14A038853
- Numbers that are divisible by 7 and are differences between two cubes in at least one way.at n=40A038855
- Numbers ending with '5' that are the difference of two positive cubes.at n=10A038860
- a(n) = (n+5)^3 - n^3.at n=11A038867