6487
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 25
- Digital Root
- 7
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 4
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 7000
- Proper Divisor Sum (Aliquot Sum)
- 513
- 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
- 5976
- Möbius Function
- 1
- Radical
- 6487
- Omega Function (Ω)
- 2
- Little Omega Function (ω)
- 2
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
- 49
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- yes
- 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
- Hex (or centered hexagonal) numbers: 3*n*(n+1)+1 (crystal ball sequence for hexagonal lattice).at n=46A003215
- Number of partitions of n in which no part occurs just once.at n=51A007690
- Coordination sequence for alpha-Mn, Position Mn1.at n=21A009950
- Character of extremal vertex operator algebra of rank 39/2.at n=3A028544
- Numbers ending with '7' that are the difference of two positive cubes.at n=34A038862
- a(n) = 2i + 1 where i is the least index such that A039508(i) = A039509(n).at n=13A039510
- Minimal absolute difference of 3^n and 2^k.at n=10A056850
- Difference between 3^n and the next larger or equal power of 2.at n=10A063003
- Difference between 2^n and the next smaller or equal power of 3.at n=16A063005
- a(n) = minimum value of abs(2^n - 3^k).at n=16A064024
- a(n) = 4^n mod 3^n.at n=8A064629
- Numbers which yield a prime whenever a 1 is inserted anywhere in them (including at the beginning or end).at n=55A068679
- a(n) = A077347(n)^(1/2).at n=41A077349
- Where records occur in A079366.at n=8A079368
- Expansion of (1+4x+7x^2)/((1-x)^2*(1-x^2)).at n=46A090381
- Number of regions that the line segments in A091908(n) cut the equilateral triangle into.at n=46A092098
- Iccanobirt numbers (12 of 15): a(n) = R(R(a(n-1)) + a(n-2) + a(n-3)), where R is the digit reversal function A004086.at n=18A102122
- Iccanobirt semiprimes (12 of 15): Semiprime numbers in A102122.at n=3A102202
- List of values of 2^ceiling(log_2(3^k)) - 3^k for k >= 1, sorted in increasing order.at n=8A102872
- Integer part of the area of consecutive prime sided tetragons with one right angle.at n=21A105270