7855
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
- 9432
- Proper Divisor Sum (Aliquot Sum)
- 1577
- 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
- 6280
- Möbius Function
- 1
- Radical
- 7855
- 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
- 83
- 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 certain self-avoiding walks with n steps on square lattice (see reference for precise definition).at n=16A006144
- Numbers k such that the continued fraction for sqrt(k) has period 88.at n=13A020427
- T(2n,n+1), T given by A026747.at n=6A026861
- Shifts left under "AFJ" (ordered, size, labeled) transform.at n=7A032004
- Shifts left under "AGJ" (ordered, elements, labeled) transform.at n=7A032018
- Numbers k such that 179*2^k+1 is prime.at n=23A032466
- Numbers k such that 197*2^k+1 is prime.at n=11A032475
- Number of partitions satisfying cn(1,5) + cn(4,5) <= cn(0,5).at n=43A039860
- Numbers whose base-4 representation contains exactly three 2's and three 3's.at n=30A045151
- a(n)=a(n-1)+a(n-2)-d, where d=a(n/4) if 4 divides n, else d=0; 2 initial terms.at n=20A050194
- a(n) = n*(7*n^2-4)/3.at n=15A063521
- Centered 14-gonal numbers.at n=33A069127
- Numbers n such that ((n-1)^2+1)/2 and n^2+1 and ((n+1)^2+1)/2 are prime if n is even or (n-1)^2+1 and (n^2+1)/2 and (n+1)^2+1 are prime if n is odd.at n=38A082612
- A Chebyshev transform of A030191 associated to the knot 7_6.at n=7A099448
- Semiprimes in A056108.at n=15A113527
- Ulam's spiral (SSW spoke).at n=22A143838
- Expansion of 1/(1 - x - x^2 + x^3 - x^7 + x^9 - x^11).at n=33A147663
- a(n) = A151723(2^n).at n=6A169785
- Number of arrays of -3..3 integers x(1..n) with every x(i) in a subsequence of length 1 or 2 with sum zero.at n=7A193643
- T(n,k)=Number of arrays of -k..k integers x(1..n) with every x(i) being in a substring of length 1 or 2 with sum zero. Array listed by antidiagonals.at n=52A193648