6446
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 20
- Digital Root
- 2
- Palindromic Number
- yes
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 10584
- Proper Divisor Sum (Aliquot Sum)
- 4138
- 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
- 2920
- Möbius Function
- -1
- Radical
- 6446
- 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
- 23
- 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
- yes
- Odd
- no
Appears in sequences
- Number of loopless rooted planar maps with 3 faces and n vertices and no isthmuses. Also a(n)=T(4,n-3), array T as in A049600.at n=30A006416
- Coordination sequence for CaF2(1), Ca position.at n=27A009923
- Coordination sequence for MgNi2, Position Ni3.at n=20A009934
- Number of partitions of n into parts not of the form 21k, 21k+2 or 21k-2. Also number of partitions with 1 part of size 1 and differences between parts at distance 9 are greater than 1.at n=36A035980
- Trajectory of 3 under map n->13n+1 if n odd, n->n/2 if n even.at n=36A037104
- First location of palindrome a(n) in decimal expansion of Pi is palindromic.at n=19A038101
- 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=19A039624
- Base-10 palindromes that start with 6.at n=16A043041
- Palindromes with exactly 3 prime factors (counted with multiplicity).at n=43A046329
- Palindromes with exactly 3 distinct prime factors.at n=28A046393
- 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=25A058229
- a(n) = n^2 + (n^2 with digits reversed).at n=35A061226
- Palindromic numbers with even digits.at n=41A062287
- Numbers k such that phi(k) divides sigma(k+1) + sigma(k).at n=42A067246
- Palindromes of length greater than 1 in decimal expansion of Pi (not showing leading 0's).at n=34A068046
- Palindromic numbers which are products of an odd number of distinct primes.at n=49A075800
- Palindromic even numbers with an odd number of distinct prime factors.at n=15A075809
- Palindromic even numbers with exactly 3 prime factors (counted with multiplicity).at n=19A075816
- Palindromic even numbers with an odd number of prime factors (counted with multiplicity).at n=37A075817
- Palindromes not divisible by any of their digits.at n=38A082947