7161
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 15
- Digital Root
- 6
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 16
- Divisor Sum
- 12288
- Proper Divisor Sum (Aliquot Sum)
- 5127
- 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
- 3600
- Möbius Function
- 1
- Radical
- 7161
- Omega Function (Ω)
- 4
- Little Omega Function (ω)
- 4
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
- 132
- 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
- Denominators of cosecant numbers: -2*(2^(2*n-1)-1)*Bernoulli(2*n).at n=15A001897
- Divisors of 2^30 - 1.at n=36A003538
- Pentagonal numbers written backwards.at n=33A004163
- Denominators of expansion of sinh x / sin x.at n=15A006656
- Denominators of expansion of sinh x / sin x.at n=30A006656
- a(n) = (n+1)*(2*n+1)*(3*n+1).at n=10A011199
- Pseudoprimes to base 29.at n=39A020157
- Pseudoprimes to base 85.at n=46A020213
- Pseudoprimes to base 92.at n=46A020220
- Strong pseudoprimes to base 64.at n=28A020290
- a(n) = floor( Sum_{1 <= i < j <= n} ((sqrt(j)-sqrt(i))^3) ).at n=34A025197
- Base 5 digits are, in order, the first n terms of the periodic sequence with initial period 2,1.at n=5A037490
- Numbers n such that lcm(sigma(n),phi(n)) is a perfect square.at n=43A043293
- Numbers whose base-5 representation contains exactly three 1's and three 2's.at n=14A045232
- 10-factorial numbers.at n=3A045757
- Numbers primitive with respect to having more than one factorization into S-primes. See related sequences for definition.at n=39A057950
- a(n) = 7*n^2 + 14*n.at n=30A067727
- Integers which have at least two different factorizations into coprime parts whose sum are equal.at n=27A069064
- Schroeder pseudoprimes: Composites k that divide the k-th Schroeder number A001003(k-1).at n=17A075764
- Pascal-(1,7,1) array.at n=39A081582