13210
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 7
- Digital Root
- 7
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 23796
- Proper Divisor Sum (Aliquot Sum)
- 10586
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 5280
- Möbius Function
- -1
- Radical
- 13210
- 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
- 138
- 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
- yes
- Odd
- no
Appears in sequences
- Squares written in base 4.at n=22A001739
- a(n) = a(1) + a(2) + ... + a(n-1) + a(m) for n >= 4, where m = n - 1 - 2^p and p is the unique integer such that 2^p < n - 1 <= 2^(p+1), starting with a(1) = 1 and a(2) = a(3) = 2.at n=14A049954
- n written efficiently in natural numbers base, i.e., in form ...wxyz where n = 1*z + 2*y + 3*x + 4*w + ... with z <= 1, y < 2, x < 3, w < 4, ...at n=24A055611
- n written efficiently in natural numbers base, i.e., in form ...wxyz where n =1*z + 2*y + 3*x + 4*w + ... with z < 1, y < 2, x < 3, w < 4, ...at n=23A055992
- Integer part of log(n!)^(1 + log(log(1 + n))).at n=28A062475
- Half the difference between the larger and smaller term of the n-th amicable pair.at n=17A162884
- a(2*n) = 10*a(n), a(2*n+1) = a(n) + a(n+1).at n=49A178569
- Numbers k such that k^2 + 1 = p*q, p and q primes and |p-q| is square.at n=28A187401
- Half the difference between the larger and smaller terms of the n-th amicable pair (x,y) given in A259933.at n=17A275470
- 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=18A317399
- Total number of partitions in the partitions of compositions of n.at n=9A326346
- Lexicographically earliest sequence of nonnegative integers such that two distinct terms differ by at least 4 decimal digits.at n=13A346000
- G.f. satisfies A(x) = ( 1 + x*A(x)^(5/2) / (1 - x)^2 )^2.at n=5A371585