3985
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 25
- Digital Root
- 7
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 4788
- Proper Divisor Sum (Aliquot Sum)
- 803
- 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
- 3184
- Möbius Function
- 1
- Radical
- 3985
- 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
- 51
- 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
- Coordination sequence T4 for Zeolite Code VNI.at n=39A009910
- arcsin(sec(x)*sinh(x))=x+5/3!*x^3+85/5!*x^5+3985/7!*x^7+379625/9!*x^9...at n=3A012815
- Numbers k such that the continued fraction for sqrt(k) has period 41.at n=8A020380
- a(n) = Sum_{k=1..n} floor((n/k)*floor(n/k)).at n=49A024921
- Numbers n such that 217*2^n-1 is prime.at n=9A050860
- a(n) = 1/2*binomial(2*n,n) - (1+(-1)^n)/4*(binomial(n,floor(n/2)))^2.at n=8A058621
- Prime(a(n)) + ... + prime(a(n)+3) is a square = A051395(n)^2.at n=11A072849
- n*nextprime((n-1)!)-nextprime(n!).at n=31A089014
- Composite de Polignac numbers (A006285).at n=39A098237
- Numbers k such that 7*10^k + 2*R_k - 1 is prime, where R_k = 11...1 is the repunit (A002275) of length k.at n=10A103052
- Integers of the form c(n)/b(n) where c(n+1)=c(n)+(n+1)^4 with c(0)=1 and b(n+1)=b(n)+(n+1)^2 with b(0)=1.at n=32A119617
- Square array a(m,n) read by antidiagonals, where a(m,n) is the number of ways to move a chess queen from the lower left corner to square (m,n), with the queen moving only up, right, or diagonally up-right.at n=48A132439
- Square array a(m,n) read by antidiagonals, where a(m,n) is the number of ways to move a chess queen from the lower left corner to square (m,n), with the queen moving only up, right, or diagonally up-right.at n=51A132439
- a(n) = 15*n^2 + 9*n + 1.at n=16A134153
- Numbers x such that for some y < sqrt(2x), x^2 + x + y^2 is an odd primitive abundant number, A136476(n).at n=44A136477
- Ulam's spiral (ESE spoke).at n=16A143855
- Number of paths of the simple random walk on condition that the median applied to the partial sums S_0=0, S_1,...,S_n, n odd (n=15 in this example), is equal to integer values k, -[n/2]<=k<=[n/2].at n=6A146206
- Number of paths of the simple random walk on condition that the median applied to the partial sums S_0=0, S_1,...,S_n, n odd (n=15 in this example), is equal to integer values k, -[n/2]<=k<=[n/2].at n=8A146206
- 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, 0, 1), (0, 1, -1), (0, 1, 1), (1, -1, 1), (1, 1, 1)}.at n=6A151006
- Partial sums of economical numbers A046759.at n=8A172460