8001
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 9
- Digital Root
- 9
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 12
- Divisor Sum
- 13312
- Proper Divisor Sum (Aliquot Sum)
- 5311
- 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
- 4536
- Möbius Function
- 0
- Radical
- 2667
- Omega Function (Ω)
- 4
- 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
- yes
- 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
- yes
- Narcissistic Number
- no
- Collatz Steps
- 52
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- no
- Squarefree Number
- no
- 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
- a(n) = n^3 + 1.at n=21A001093
- Divisors of 2^42 - 1.at n=30A003547
- a(n) = p*(p-1)/2 for p = prime(n).at n=30A008837
- Numbers k such that k^2 and k have same last 3 digits.at n=33A008853
- Numbers k that divide s(k), where s(1)=1, s(j)=9*s(j-1)+j.at n=34A014857
- Numbers k such that k divides 4^k - 1.at n=38A014945
- Numbers k such that k | 5^k + 1.at n=36A015951
- a(n) = (2*n-1)*(4*n-1).at n=32A033567
- a(n) = (n^2-1)*(2*n^2-1).at n=8A033595
- Decimal part of cube root of a(n) starts with 0: first term of runs (cubes excluded).at n=18A034126
- (s(n)+2)/10, where s(n)=n-th base 10 palindrome that starts with 8.at n=22A043087
- Numbers whose base-6 representation has exactly 6 runs.at n=2A043614
- Numbers k that divide 10^k + 2^k.at n=50A045583
- Numbers k that divide 5^k + 4^k.at n=27A045590
- Numbers k that divide 10^k + 8^k.at n=44A045608
- Numbers whose 4th power can be expressed as the sum of two positive cubes in more than one way.at n=5A051388
- Number of asymmetric digraphs with n nodes.at n=5A051504
- Integers > 1 whose prime divisors are all Mersenne primes (i.e., of the form (2^p - 1)).at n=48A056652
- Numbers k such that k | 6^k + 5^k + 4^k + 3^k + 2^k + 1^k.at n=39A056745
- Numbers n such that n | 12^n + 11^n + 10^n + 9^n.at n=46A057239