16789
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 31
- Digital Root
- 4
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 17056
- Proper Divisor Sum (Aliquot Sum)
- 267
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 16524
- Möbius Function
- 1
- Radical
- 16789
- 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
- 66
- 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
- Numerators of continued fraction convergents to sqrt(382).at n=6A041724
- Look at the first 10 digits of the sequence: they are all different. The same for the next 10. And the next 10, etc. This sequence is the slowest increasing one with that property.at n=49A097912
- Append three digits, each increasing by one modulo 10 from the last digit of the nonnegative integers. 0 -> 123, 1 -> 1234 2 -> 2345, ... , 9 -> 9012, 10 -> 10123, etc.at n=16A167231
- Smallest number with n = sum of distinct digits in decimal representation, cf. A217928.at n=31A227378
- Solution of the complementary equation a(n) = a(n-1) + a(n-2) + b(n) + 1, where a(0) = 1, a(1) = 4, b(0) = 2, b(1) = 3, b(2) = 5, and (a(n)) and (b(n)) are increasing complementary sequences.at n=16A295957
- Expansion of (1/(1 - x))*Product_{k>=1} (1 + k*x^k).at n=18A302831
- Number of partitions of n with up to four distinct kinds of 1.at n=32A320691
- Number of compositions of n with all adjacent parts (x, y) satisfying x > 2y or y > 2x.at n=27A342332
- a(n) is the least positive integer that has exactly n anagrams that are semiprimes, or -1 if there is no such integer.at n=44A362499
- a(n) is the smallest error in trying to solve n^5 = x^5 + y^5: for each n from 2 on, find positive integers x and y, x <= y < n such that |n^5 - x^5 - y^5| is minimal and let a(n) = n^5 - x^5 - y^5. In case of a tie, choose the solution with smallest y.at n=13A369855