7745
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 23
- Digital Root
- 5
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 9300
- Proper Divisor Sum (Aliquot Sum)
- 1555
- 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
- 6192
- Möbius Function
- 1
- Radical
- 7745
- 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
- yes
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 52
- 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
- Pseudoprimes to base 88.at n=37A020216
- Strong pseudoprimes to base 88.at n=10A020314
- Number of partitions of n that do not contain 5 as a part.at n=34A027339
- Number of inequivalent binary [ n,3 ] codes of dimension <= 3 without zero columns.at n=26A034337
- a(n) = T(6,n), array T given by A048471.at n=5A036547
- Numbers having four 5's in base 6.at n=15A043392
- Numbers having three 5's in base 9.at n=33A043475
- Triangle T(n,k) of numbers of k-covers of an unlabeled n-set, k=1..2^n-1.at n=31A055130
- Both m and its reverse are one more than a square and m does not end in 0.at n=6A066618
- a(n) is the first term of the first run of exactly n non-perfect-powers.at n=30A087646
- Numbers whose set of base 6 digits is {0,5}.at n=29A097252
- a(n) = 16*n^2 + 1.at n=21A108211
- Numbers k such that k*(k+4) gives the concatenation of two numbers m and m+4.at n=0A116317
- a(n) = Sum_{k=1..phi(n)-1} t(n,k)*t(n,k+1), where t(n,k) is the k-th positive integer which is coprime to n and phi(n) is the number of positive integers which are <= n and are coprime to n.at n=39A119584
- Composite number of the form 4n^2+1.at n=27A121944
- Both k and its reverse are one more than a square.at n=11A124664
- Semiprimes of the form k^2+1.at n=40A144255
- a(n) = 6^n - 2^n + 1.at n=5A155597
- a(n) = 242*n + 1.at n=31A157958
- a(n) = 484*n + 1.at n=15A158326