8445
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 21
- Digital Root
- 3
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 13536
- Proper Divisor Sum (Aliquot Sum)
- 5091
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Highly Composite
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 4496
- Möbius Function
- -1
- Radical
- 8445
- 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
- 171
- 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
- no
- Odd
- yes
Appears in sequences
- Numbers whose set of base-14 digits is {1,3}.at n=23A032921
- a(n) = a(n-1) + a(m) for n >= 4, where m = 2*n - 3 - 2^(p+1) and p is the unique value such that 2^p < n - 1 <= 2^(p+1), starting with a(1) = a(2) = 1 and a(3) = 3.at n=32A050032
- a(n) = a(n-1) + a(m) for n >= 3, where m = 2*n - 3 - 2^(p+1) and p is the unique integer such that 2^p < n - 1 <= 2^(p+1), starting with a(1) = 1 and a(2) = 2.at n=32A050048
- a(n) = a(n-1) + a(m) for n >= 4, where m = 2*n - 3 - 2^(p+1) 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) = 3.at n=32A050064
- Numbers n such that both n^4 + 2 and n^4 - 2 are prime.at n=35A071351
- Interprimes which are of the form s*prime, s=15.at n=30A075290
- Numbers k such that k*(k+7) gives the concatenation of two numbers m and m+3.at n=0A116311
- G.f. satisfies: 30*A(x) = 29 + 125*x + A(x)^5, starting with [1,5,10].at n=5A120598
- Number of n X n binary arrays symmetric about main diagonal with all ones connected only in a 1111-1111 pattern in any orientation.at n=12A146936
- Number of n X n binary arrays symmetric about the diagonal and under 90 degree rotation with all ones connected only in a 1111-1111 pattern in any orientation.at n=26A146938
- Composites that are the sum of two, three, four and five consecutive composite numbers.at n=12A151745
- Sums of three Mersenne primes.at n=29A174055
- Numbers that are the product of 3 distinct primes a,b and c, such that a+b+c, a^2+b^2+c^2 and a^3+b^3+c^3 are prime numbers.at n=14A176911
- Numbers k such that 3*R_(k+2) + 2*10^k is prime, where R_k = 11...1 is the repunit (A002275) of length k.at n=20A256788
- Triangle read by rows: T(n,k) = number of partial idempotent mappings (of an n-chain) with (right) waist exactly k.at n=35A258579
- a(n) = number of n-digit binary numbers in which the first k and last k digits have a Hamming distance of 1 or less, for all k from 1 to n.at n=39A288793
- Number of partitions of n in which the sequence of the sum of the same summands is nondecreasing.at n=42A304405
- a(n) is the number of partitions of 72*n + 42 into 10 odd squares.at n=30A323891
- G.f. A(x) satisfies: Sum_{n>=0} x^n * A(x)^(n^2) = Sum_{n>=0} x^n / [Product_{k=1..n} 1 - (2*k-1)*x].at n=7A325453
- Expansion of e.g.f. exp(x * (2 + exp(x))).at n=6A367874