13984
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 25
- Digital Root
- 7
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 4
Divisibility
- Divisor Count
- 24
- Divisor Sum
- 30240
- Proper Divisor Sum (Aliquot Sum)
- 16256
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 6336
- Möbius Function
- 0
- Radical
- 874
- Omega Function (Ω)
- 7
- 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
- 120
- Smith Number
- yes
- 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
- yes
- Odd
- no
Appears in sequences
- a(1) = 1; thereafter a(n+1) = floor(sqrt(2*a(n)*(a(n)+1))).at n=26A001521
- Least k such that k and 4k are anagrams in base n (written in base 10).at n=42A023096
- a(n) is least k such that k and 6k are anagrams in base n (written in base 10).at n=17A023098
- Numbers k such that the continued fraction for sqrt(k) has even period and if the last term of the periodic part is deleted the central term is 59.at n=28A031557
- Numbers whose base-7 representation contains exactly four 5's.at n=17A043416
- Sum{T(i,n-i): i=0,1,...,n}, array T given by A047010.at n=15A047011
- Lesser members of g-reduced amicable pairs a < b such that sigma(a) = sigma(b) = a + b + gcd(a,b).at n=35A054573
- McKay-Thompson series of class 50a for Monster.at n=63A058703
- Smallest n-aspiring number. That is, a(n) = smallest k such that s^(n)(k) is perfect but s^(n-1)(k) is not, where s(k) is the sum of the aliquot parts of k and s^(i) means iterate s i times.at n=8A099771
- a(n) = n*(14*n - 11).at n=32A195021
- a(n) = (n-2)*(14*n-39) for n > 2, otherwise a(n) = n.at n=34A195030
- Number of n X n 0..2 symmetric matrices with every element equal to zero, two, three or four horizontal and vertical neighbors, and new values 0..2 introduced in lower triangle row major order.at n=4A210910
- At stage 1, start with a unit equilateral triangle. At each successive stage add 3*(n-1) new triangles around outside with vertex-to-vertex contacts. Sequence gives number of triangles at n-th stage.at n=32A269064
- Numbers which are representable as a sum of nineteen but no fewer consecutive nonnegative integers.at n=14A270303
- Number of singleton-free multiset partitions of integer partitions of n with no 1's.at n=27A320291
- Number of integer partitions of n containing all of their distinct multiplicities.at n=43A325705
- Integers k such that for all m>k, d(m)/m < d(k)/k where d(j) = Min_{p & q odd primes, 2*j = p+q, p <= q} (q-p)/2.at n=20A335297
- Numbers k such that the odd part of sigma(sigma(k)) is equal to the odd part of sigma(k).at n=40A353365
- Numbers k such that A360119(k) > 1, but which have no divisors d > 1 such that d+1 is also a divisor.at n=31A360129