4065
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 15
- Digital Root
- 6
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 6528
- Proper Divisor Sum (Aliquot Sum)
- 2463
- 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
- 2160
- Möbius Function
- -1
- Radical
- 4065
- 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
- yes
- Narcissistic Number
- no
- Collatz Steps
- 126
- 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
- Reverse digits of number of partitions of n.at n=30A004089
- Coordination sequence T3 for Zeolite Code MEL.at n=41A008152
- Expansion of 1/((1-2x)(1-9x)(1-10x)).at n=3A016321
- a(n) = n*(9*n + 1)/2.at n=30A022267
- Numbers k that divide the (right) concatenation of all numbers <= k written in base 25 (most significant digit on left).at n=42A029470
- a(n) = (n - 1)*(n^2 + n - 1).at n=16A033445
- "Sloping binary representation" of powers of 3 (A000244), slope = -1.at n=19A037095
- Expansion of (1-x)/(1 - x - 2*x^3 + x^4).at n=22A052916
- a(n) = 4*n^2 - 9*n + 6.at n=32A054556
- Number of periodic palindromic structures of length n using exactly five different symbols.at n=15A056511
- Numbers k such that 3*2^k + 35 is prime.at n=37A059759
- Numbers n such that sigma(n+1)=3*phi(n).at n=47A067261
- Numbers k for which 10*2^k + 3 is a prime (giving terms of A068712).at n=39A068713
- Interprimes which are of the form s*prime, s=15.at n=22A075290
- a(n) = (concatenation of numbers from n to 1) - n^n.at n=3A083453
- n sets a new record for number of iterations to reach 1 in the juggler sequence problem.at n=12A094679
- Arithmetic derivative of n-th partition number.at n=31A096371
- Numbers k such that (k + prime(k)) and (k+1 + prime(k+1)) are divisible by 11.at n=38A107380
- a(0)=1, a(1)=2, a(2)=3, a(3)=5, a(4)=7, a(5)=10; a(n) = floor(a(n-1) + 1 + a(n-2)/6) for n>=6.at n=47A119565
- a(n) = A127359(n+1)/2 - A127359(n).at n=7A126931