16243
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 16
- Digital Root
- 7
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 16720
- Proper Divisor Sum (Aliquot Sum)
- 477
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 15768
- Möbius Function
- 1
- Radical
- 16243
- 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
- 40
- 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
- Numbers that define integer Heronian triangles [prime(a(n)), prime(a(n)+1), A068965(n)] with area A068966(n).at n=20A068964
- a(n) = n*(2*n^2 -3*n +7)/6 = C(n, 1) + C(n, 2) + 2*C(n, 3).at n=36A081489
- a(n) = sum of the first n lower twin primes.at n=38A086167
- Numbers n such that 2^(n+1)+2n+1 is prime.at n=32A105330
- Greatest n-bit number whose binary representation's substrings represent the maximal number (A112509(n)) of distinct integers.at n=13A112511
- Number of base 23 circular n-digit numbers with adjacent digits differing by 5 or less.at n=4A125386
- Real part of Sum_{k=0..n} (k + i^k)^2, where i=sqrt(-1).at n=36A236377
- Number of n-node unlabeled rooted trees with thickening limbs.at n=21A245152
- Number of compositions of n such that the maximal distance between two identical parts equals one.at n=24A262192
- a(n) = (1/n) * Sum_{k=1..n} k * lcm(k,n).at n=36A344509