13705
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
- 1
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 16452
- Proper Divisor Sum (Aliquot Sum)
- 2747
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 10960
- Möbius Function
- 1
- Radical
- 13705
- 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
- 151
- 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
- Number of ways writing 2^n as unordered sums of 2 primes.at n=22A006307
- a(1) = 2; a(n+1) = a(n)-th composite.at n=35A022450
- Number of partitions of n that do not contain 4 as a part.at n=38A027338
- Start of record gap in odd semiprimes A046315.at n=8A114057
- Expansion of e.g.f. Product_{i>=1} (1 + x^i)^(1/i).at n=8A168243
- Number of Goldbach partitions of 4^n.at n=11A195295
- a(n) = number of n-lettered words in the alphabet {1, 2, 3} with as many occurrences of the substring (consecutive subword) [1, 1, 2] as of [1, 2, 1].at n=9A211289
- Idempotent equivalence class multiplications for the full transformation semigroup.at n=3A285051
- Square array A(n,k), n >= 0, k >= 0, read by antidiagonals, where column k is the expansion of e.g.f.: exp(1/(1-x)^k - 1).at n=49A294046
- Expansion of e.g.f.: exp(1/(1-x)^5 - 1).at n=4A294051
- Number of parts in all partitions of n in which no part occurs more than six times.at n=25A320609
- Non-Brauer numbers.at n=2A349044
- a(n) is the lower end of a record gap A349995(n) between consecutive odd squarefree semiprimes (A046388).at n=7A350098