10521
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 9
- Digital Root
- 9
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 12
- Divisor Sum
- 17472
- Proper Divisor Sum (Aliquot Sum)
- 6951
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 5976
- Möbius Function
- 0
- Radical
- 3507
- Omega Function (Ω)
- 4
- 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
- yes
- Harshad Number
- yes
- Narcissistic Number
- no
- Collatz Steps
- 104
- 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
- Vampire numbers: (definition 1): n has a nontrivial factorization using n's digits.at n=18A020342
- Successive left concatenation of floor(k/2) beginning with n until we reach 1.at n=9A068657
- Expansion of 1/(1-x-x^2+2*x^3).at n=37A077948
- Record-setting differences between adjacent elements of the Mian-Chowla sequence variant A058335.at n=39A080931
- a(n) = n^3 + 6*n^2 + 6*n + 1.at n=20A090197
- 3-Smith numbers.at n=32A104391
- Triangle read by rows: T(n,k) is the number of Grand Dyck paths of semilength n that have k double rises above the x-axis (n >= 1, k >= 0).at n=50A118964
- Exponential Riordan array [e^(x/(1-x)),x].at n=30A129652
- a(n) = n*(2*n^2 + 5*n + 15)/2.at n=21A163673
- a(n) = A170907(2^n).at n=7A163862
- a(n) is the reverse concatenation of divisors of n.at n=9A176558
- a(n) = A176558(A175354(n)) = numbers m as reverse concatenations of divisors of numbers from A175354, where A175354 = numbers k such that reverse concatenations of divisors of k are nonprimes.at n=6A176588
- An Ulam-type sequence: a(n) = n if n<=10; for n>10, a(n) = least number > a(n-1) which is a unique sum of 10 distinct earlier terms.at n=43A183533
- Triangle of coefficients of polynomials v(n,x) jointly generated with A210600; see the Formula section.at n=40A210601
- Number of length 5 1..(n+1) arrays with every leading partial sum divisible by 2, 3 or 5.at n=7A254832
- Number of (not necessarily maximal) cliques in the n-Sierpinski carpet graph.at n=3A295932
- Partial sums of A108754.at n=34A307673
- Number of integer compositions of n with all prime run-lengths.at n=28A353401
- The positive odd numbers x such that x = c^2 - y and +-x = a +- y, where (a,b,c) is a primitive Pythagorean triple (PPT), a is odd and y is an even positive integer.at n=22A357535