13129
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 16
- Digital Root
- 7
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 13840
- Proper Divisor Sum (Aliquot Sum)
- 711
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 12420
- Möbius Function
- 1
- Radical
- 13129
- Omega Function (Ω)
- 2
- 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
- 76
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- yes
- 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
- Numbers that are the sum of 9 nonzero 8th powers.at n=19A003387
- Expansion of tan(x)*cosh(sin(x)) (odd powers only).at n=4A009732
- Expansion of tan(x)*exp(sin(x)).at n=9A009735
- a(n) = s(1)t(n) + s(2)t(n-1) + ... + s(k)t(n+1-k), where k = [ (n+1)/2 ], s = (F(2), F(3), ...), t = A000201 (lower Wythoff sequence).at n=22A024593
- Number of partitions of n into an even number of parts, the least being 2; also, a(n+2) = number of partitions of n into an odd number of parts, each >=2.at n=50A027194
- Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 82 ones.at n=7A031850
- Numbers which contain exactly the same digits (with the correct multiplicity) in 3 different smaller bases.at n=22A059828
- Composite numbers whose divisors (except 1) all contain the digit 9.at n=21A062680
- Numbers k such that k and its reversal are both multiples of 19.at n=37A062907
- Non-palindromic number and its reversal are both multiples of 19.at n=26A062916
- Indices n of primes p(n), p(n+4) such that p(n)+1 and p(n+4)+1 have the same largest prime factor.at n=12A105408
- Semiprimes whose factors are decimal palindromes when concatenated, omitting multiples of primes less than 11.at n=35A144719
- Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, -1, 1), (-1, 0, 1), (0, 0, 1), (1, -1, 0), (1, 1, -1)}.at n=9A148468
- Triangle read by rows in which row n lists n+1 terms, starting with n, such that the difference between successive terms is equal to n^4 - 1.at n=47A162622
- Triangle read by rows in which row n lists n terms, starting with n, such that the difference between successive terms is equal to n^4 - 1 = A123865(n).at n=38A162623
- Triangle read by rows in which row n lists n terms, starting with n^4 + n - 1, such that the difference between successive terms is equal to n^4 - 1 = A123865(n).at n=37A162624
- a(n) = floor( prime(n)^3 / (n*log(n)) ).at n=26A259648
- a(n) is the smallest number that is the sum of n positive 6th powers in two ways.at n=22A343079
- a(n) is the least k such that A033273(k) is equal to (A033273(n*k + 1) - 1)/n where A033273(n) is the number of nonprime divisors of n.at n=22A352256
- Indices where the cumulative sum of sin(2k+1)^(2k+1) reaches a record high value.at n=26A387706