16471
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 19
- Digital Root
- 1
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 4
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 20384
- Proper Divisor Sum (Aliquot Sum)
- 3913
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 12960
- Möbius Function
- -1
- Radical
- 16471
- 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
- yes
- Perfect Square
- no
- Perfect Cube
- no
- Pentagonal Number
- no
- Hexagonal Number
- yes
- Lucas Number
- no
- Tetrahedral Number
- no
- Pell Number
- no
- Tribonacci Number
- no
- Pronic Number
- no
Recreational
- Happy Number
- yes
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 115
- 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
- no
- Odd
- yes
Appears in sequences
- Pseudoprimes to base 3.at n=30A005935
- Numbers k such that k | 7^k + 7.at n=27A015893
- Strong pseudoprimes to base 9.at n=20A020235
- Strong pseudoprimes to base 12.at n=12A020238
- Strong pseudoprimes to base 29.at n=14A020255
- Strong pseudoprimes to base 81.at n=30A020307
- Numbers whose set of base-11 digits is {1,4}.at n=35A032823
- Triangular numbers (A000217) with prime indices.at n=41A034953
- Odd triangular numbers with prime indices.at n=19A034954
- Composite numbers k, not a power of 2, such that the E(k) == 1 (mod k), where E(k) is the k-th Euler number (A000364).at n=41A035163
- Numbers whose base-4 representation contains exactly three 0's and four 1's.at n=21A045032
- a(n) = n^4 - (n-1)^4 + (n-2)^4 - ... 0^4.at n=13A062392
- Doubly hexagonal numbers.at n=7A063249
- Triangular numbers with property that swapping first and last digits also gives a triangular number.at n=38A069708
- Triangular numbers which are also happy numbers (cf. A007770).at n=27A076712
- Duplicate of A062392.at n=12A088058
- Triangular numbers with palindromic indices.at n=27A089717
- Row sums of triangle A093922.at n=16A093925
- a(n) = k*a(n-1) + a(n-2) where k = A003842(a); a(0) = 1.at n=16A108282
- a(n) = a(n-2) + A000265(a(n-1)), a(0)=0, a(1)=1.at n=33A114990