13573
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
- 3
Divisibility
- Divisor Count
- 6
- Divisor Sum
- 15846
- Proper Divisor Sum (Aliquot Sum)
- 2273
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 11592
- Möbius Function
- 0
- Radical
- 1939
- Omega Function (Ω)
- 3
- 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
- 45
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- no
- Squarefree Number
- no
- 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
- a(n) = (d(n)-r(n))/2, where d = A026066 and r is the periodic sequence with fundamental period (1,0,0,0).at n=42A026067
- Numbers that are the product of 3 prime factors whose concatenation is a palindrome.at n=29A046452
- Numbers k such that 299*2^k + 1 is prime.at n=26A053366
- Triangle of Salie numbers.at n=31A065547
- a(n) = 16*n^2 + 4*n + 1.at n=29A082041
- Triangular array A065547 unsigned and transposed.at n=32A085707
- Fourth column of Salié-triangle A065547.at n=4A095652
- Number of squares (of nonnegative integers) that require n binary (base-2) digits.at n=31A126726
- a(n) is the ceiling of 2^n * (sqrt(2)-1), i.e., a(n)-1 is the number whose binary representation gives the first n bits of sqrt(2)-1.at n=14A136322
- Number of binary strings of length n with no substrings equal to 0001, 0110, or 1110.at n=27A164482
- a(n) has generating function 1/((1-x)^k*(1-x^2)^(k*(k-1)/2)) for k=7.at n=6A181479
- Number of triangular numbers T(k) between powers of 2, 2^(n-1) < T(k) <= 2^n.at n=30A190660
- Numbers n such that the greatest prime divisor p of n^2+1 has the property that (p - n)^2 + 1 = p.at n=40A206246
- Number of semistandard Young tableaux over all partitions of 6 with maximal element <= n.at n=7A210428
- Number of (w,x,y) with all terms in {0,...,n} and |w-x| + |x-y| + |y-w| >= w + x + y.at n=35A213489
- Begin with a(0) = 3. Let a(n) for n > 0 be the smallest positive integer not yet in the sequence which forms part of a Primitive Pythagorean Triple (PPT) when paired with a(n-1).at n=38A239356
- Numbers n such that the sum of the digits of the numbers from 0 to n is a square.at n=45A271626
- Arithmetic derivative of the prime-factorization representation of the n-th Stern polynomial: a(n) = A003415(A260443(n)).at n=44A278544
- a(n) = 9*n^2 - 3*n + 1 with n>0.at n=38A304163
- Positive integers that have exactly nine representations of the form 1 + p1 * (1 + p2* ... * (1 + p_j)...), where [p1, ..., p_j] is a (possibly empty) list of distinct primes.at n=20A317399