16523
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 17
- Digital Root
- 8
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 18816
- Proper Divisor Sum (Aliquot Sum)
- 2293
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 14400
- Möbius Function
- -1
- Radical
- 16523
- 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
- Truncated triangular pyramid numbers: a(n) = (n-5)*(n^2 + 8*n - 66)/6.at n=40A051939
- Integers n > 10583 such that the 'Reverse and Add!' trajectory of n joins the trajectory of 10583.at n=8A066055
- Basis for code in A075926.at n=10A075927
- Indices of primes in sequence defined by A(0) = 73, A(n) = 10*A(n-1) + 23 for n > 0.at n=7A101144
- Number of scalene triangles, distinct up to congruence, on an n X n grid (or geoboard).at n=17A190313
- Sequence of pairs k,g such that k*2^n-1, k*2^n-1+g, k*2^n-1+2*g, and k*2^n+3*g are four consecutive primes in arithmetic progression for the smallest odd k.at n=42A230699
- Main diagonal of Ludic array A255127 (and A255129): a(n) = A255127(n,n).at n=22A255410
- Numbers n such that n^1024 + (n+1)^1024 is prime.at n=24A274234
- Odd squarefree numbers n > 1 such that lambda(n)^2 = phi(n), where lambda is the Carmichael lambda function and phi is Euler's totient function.at n=17A276980
- Maximally idempotent integers with three or more factors.at n=28A306812
- Numbers k such that phi(k) and phi(k+1) are perfect powers (A001597).at n=39A332008
- Sphenic numbers k such that floor(log(k)/log(lpf(k))) = 1+floor(log(k)/log(p)) for all primes p | k such that p > lpf(k), where lpf = A020639(k).at n=36A383177