6464
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
- 3
Divisibility
- Divisor Count
- 14
- Divisor Sum
- 12954
- Proper Divisor Sum (Aliquot Sum)
- 6490
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Highly Composite
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- yes
Derived Values
- Euler's Totient
- 3200
- Möbius Function
- 0
- Radical
- 202
- Omega Function (Ω)
- 7
- 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
- 31
- 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
- yes
- Odd
- no
Appears in sequences
- Number of Costas arrays of order n, counting rotations and flips as distinct.at n=19A008404
- Convolution of natural numbers with composite numbers.at n=26A023539
- Numbers that are the sum of 4 nonzero squares in exactly 7 ways.at n=36A025363
- Numbers with 14 divisors.at n=27A030632
- Numbers k such that the continued fraction for sqrt(k) has even period and if the last term of the periodic part is deleted the central term is 39.at n=27A031537
- Number of partitions of n with equal nonzero number of parts congruent to each of 1, 2 and 3 (mod 5).at n=58A035588
- Numbers n such that there are equal numbers of 0's and 1's in first n digits of binary representation of Pi.at n=21A039624
- Digits d in decimal expansion of n replaced with d^3.at n=44A048390
- Digits composite, each digit minus 1 is prime, sum of digits minus 1 is prime, difference of digits (in absolute value) minus 1 is prime.at n=26A058229
- Numbers of the form (10*a + b)^2 + (10*b + a)^2 with a and b less than 10, in numerical order.at n=29A061191
- Number of (binary) bit strings of length n in which an odd length block of 0's is followed by an odd length block of 1's.at n=11A065495
- 1/n has period 4 in base 10.at n=29A069858
- Numbers whose divisors can be partitioned in exactly one way into two disjoint sets with the same sum.at n=46A083209
- Nonprimes in A084111.at n=38A084112
- A Chebyshev transform of the first kind of the Catalan numbers.at n=10A102880
- a(1) = 999, a(n) is the number obtained by concatenating product of neighboring digits of the previous term.at n=3A110401
- G.f.: A(x) = ( G(x)^7 - G(x^7) - 7*x*((1-x^6)/(1-x))/(1-x^7) )/(49*x^2) where G(x) is the g.f. of A110635.at n=8A111584
- a(n) = 5*n^2 + 20*n + 4.at n=33A134547
- Concatenation of first two digits and last two digits of n-th even superperfect number A061652(n).at n=3A138869
- Concatenation of first 3 digits and last 3 digits of n-th even superperfect number A061652(n).at n=3A138872