1812
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 12
- Digital Root
- 3
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 12
- Divisor Sum
- 4256
- Proper Divisor Sum (Aliquot Sum)
- 2444
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Highly Composite
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 600
- Möbius Function
- 0
- Radical
- 906
- Omega Function (Ω)
- 4
- 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
- yes
- Harshad Number
- yes
- Narcissistic Number
- no
- Collatz Steps
- 16
- 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 partitions into one kind of 1's, two kinds of 2's, and three kinds of 3's.at n=23A002597
- a(n) = Sum_{k=0..n} k!*(n - k)!.at n=6A003149
- Numbers n such that n^32 + 1 is prime.at n=33A006315
- a(n) = Sum_{k=1..n-1} k XOR n-k.at n=50A006582
- Unique period lengths of primes mentioned in A007615.at n=39A007498
- Number of winning (or reformed) decks at Mousetrap.at n=7A007709
- Number of fullerenes with 2n vertices (or carbon atoms).at n=20A007894
- Number of nonsplit type 2 metacyclic 2-groups of order 2^n.at n=52A007981
- Coordination sequence T1 for Zeolite Code AST.at n=31A008036
- Coordination sequence T8 for Zeolite Code MFI.at n=27A008171
- Coordination sequence T5 for Zeolite Code MFS.at n=26A008177
- Coordination sequence T3 for Zeolite Code -ROG.at n=32A009861
- Numbers n such that phi(n) * sigma(n) + 4 is a perfect square.at n=35A015727
- Index of 3^n within sequence of numbers of form 2^i*3^j (A003586).at n=47A022330
- Number of partitions of n into 9 unordered relatively prime parts.at n=27A023029
- a(n) = floor( (2nd elementary symmetric function of S(n))/(first elementary symmetric function of S(n)) ), where S(n) = {first n+1 positive integers congruent to 1 mod 3}.at n=48A024219
- Index of 8^n within the sequence of the numbers of the form 3^i*8^j (A025615).at n=43A025728
- a(n) = T(2n,n), T given by A026725.at n=6A026726
- Greatest number in row n of array T given by A026725.at n=12A026731
- a(n) = n^2 + n + 6.at n=42A027691