16761
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 21
- Digital Root
- 3
- Palindromic Number
- yes
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 23104
- Proper Divisor Sum (Aliquot Sum)
- 6343
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 10800
- Möbius Function
- -1
- Radical
- 16761
- 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
- Palindromic Super-2 Numbers.at n=28A032750
- Composite palindromes whose sum of prime factors is palindromic (counted with multiplicity).at n=27A046354
- Composite palindromes whose sum of prime factors is prime (counted with multiplicity).at n=39A046365
- Palindromic odd composite numbers that are the products of an odd number of distinct primes.at n=35A075808
- Palindromes whose product of digits is a positive palindrome.at n=43A082207
- a(n) = 2^n + Fibonacci(n).at n=14A117591
- Primitive numbers in A158235.at n=22A158245
- a(n) = 58*n^2 - 1.at n=16A158668
- Numbers n such that n^3 can be represented as sum of (at least two) consecutive squares.at n=7A163390
- Palindromic mountain numbers.at n=31A173070
- Numbers k such that k^k = k (mod prime(k)).at n=5A177005
- Least entry in a 2-composition of n, summed over all 2-compositions of n. A 2-composition of n is a nonnegative matrix with two rows, such that each column has at least one nonzero entry and whose entries sum up to n.at n=15A181366
- 1/9 the number of (n+1) X (n+1) 0..2 arrays with all 2 X 2 subblocks having the same four values.at n=11A184040
- Smallest palindrome beginning with n-th prime.at n=38A185267
- Indices of decagonal numbers that are also heptagonal.at n=3A203410
- Integers m such that m^3 is the sum of two or more consecutive integer squares.at n=18A212018
- Number of (w,x,y,z) with all terms in {1,...,n} and 3w<x+y+z+n.at n=12A212249
- Numbers n for which the numbers 6n+1, 3n+2, 6n+7 are all odd composite squarefree numbers, but none are semiprimes.at n=25A263510
- Number of integers in n-th generation of tree T(3^(-1/3)) defined in Comments.at n=54A274159
- Palindromes whose product of digits are palindromes with at least two digits.at n=2A309787