16257
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 21
- Digital Root
- 3
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 21680
- Proper Divisor Sum (Aliquot Sum)
- 5423
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 10836
- Möbius Function
- 1
- Radical
- 16257
- 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
- 71
- 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
- Divisors of 2^42 - 1.at n=32A003547
- a(n) = 4^n - 2^n + 1.at n=7A020515
- Numbers n such that 81*2^n-1 is prime.at n=18A050566
- a(n) = p^2 + p + 1 where p runs through the primes.at n=30A060800
- Numbers of the form 2^k+1 or 4^k-2^k+1.at n=20A064386
- Triangular array read by rows: row s contains integers of the form (2^s+1)/(2^r+1) in order of increasing r <= s-1.at n=21A079665
- Numbers n such that the last 9 decimal digits of the n-th Fibonacci number is pandigital 1-9.at n=4A112371
- a(1)=1, a(2)=2, a(n)=a(n-1)+floor(a(n-2)*a(n-1)/(a(n-2)+a(n-1))).at n=29A173090
- a(n) = abs(2^n-127).at n=14A176303
- G.f.: exp( Sum_{n>=1} A206152(n)*x^n/n ), where A206152(n) = Sum_{k=0..n} binomial(n,k)^(n+k).at n=4A206151
- Numbers arising in computing the Turan function of cycles of length 4.at n=33A217004
- Hilltop maps: number of n X 2 binary arrays indicating the locations of corresponding elements not exceeded by any king-move neighbor in a random 0..3 n X 2 array.at n=6A218236
- Hilltop maps: number of nX7 binary arrays indicating the locations of corresponding elements not exceeded by any king-move neighbor in a random 0..3 nX7 array.at n=1A218241
- T(n,k)=Hilltop maps: number of nXk binary arrays indicating the locations of corresponding elements not exceeded by any king-move neighbor in a random 0..3 nXk array.at n=29A218242
- T(n,k)=Hilltop maps: number of nXk binary arrays indicating the locations of corresponding elements not exceeded by any king-move neighbor in a random 0..3 nXk array.at n=34A218242
- Hilltop maps: number of nX7 binary arrays indicating the locations of corresponding elements not exceeded by any horizontal, diagonal or antidiagonal neighbor in a random 0..3 nX7 array.at n=1A218637
- T(n,k)=Hilltop maps: number of nXk binary arrays indicating the locations of corresponding elements not exceeded by any horizontal, diagonal or antidiagonal neighbor in a random 0..3 nXk array.at n=29A218638
- Numbers n of the form p^2+p+1 (for prime p) such that n^2+n+1 is also prime.at n=4A237360
- Decimal representation of the diagonal from the corner to the origin of the n-th stage of growth of the two-dimensional cellular automaton defined by "Rule 133", based on the 5-celled von Neumann neighborhood.at n=13A286020
- Decimal representation of the diagonal from the corner to the origin of the n-th stage of growth of the two-dimensional cellular automaton defined by "Rule 197", based on the 5-celled von Neumann neighborhood.at n=13A286648