16195
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 22
- Digital Root
- 4
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 20160
- Proper Divisor Sum (Aliquot Sum)
- 3965
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 12480
- Möbius Function
- -1
- Radical
- 16195
- 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
- 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
- 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
- Decimal part of cube root of a(n) starts with 3: first term of runs.at n=23A034129
- a(1) = 1, a(2) = 2, a(n) = sum of products of previous terms taking n-2 at a time.at n=5A061482
- a(n) = (A216363(n) - 1)/118.at n=34A216380
- Partial sums of 3-almost primes which are again 3-almost primes, i.e., have exactly 3 not necessarily distinct prime factors.at n=24A217018
- Number of partitions p of n such that 2*(number of even numbers in p) < (number of odd numbers in p).at n=45A241651
- Smallest number x such that sigma(x) = sigma(x(n)), where x(n) is the n-th arithmetic derivatives of x and x is not equal to x(n).at n=11A246774
- Numbers k with the property that it is possible to write the base 2 expansion of k as concat(a_2,b_2), with a_2>0 and b_2>0 such that, converting a_2 and b_2 to base 10 as a and b, we have sigma(a + b) = sigma(k).at n=14A258843
- Index of 2^n in A280864.at n=14A280746
- Number of nX6 0..1 arrays with every element unequal to 0, 1, 3, 5, 6 or 7 king-move adjacent elements, with upper left element zero.at n=6A306170
- Number of nX7 0..1 arrays with every element unequal to 0, 1, 3, 5, 6 or 7 king-move adjacent elements, with upper left element zero.at n=5A306171