7001
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 8
- Digital Root
- 8
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 7002
- Proper Divisor Sum (Aliquot Sum)
- 1
- 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
- 7000
- Möbius Function
- -1
- Radical
- 7001
- Omega Function (Ω)
- 1
- Little Omega Function (ω)
- 1
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
- 31
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- yes
- Composite Number
- no
- Semiprime
- no
- Squarefree Number
- yes
- Prime Power
- yes
- Prime Factorization
- no
- Twin Prime
- no
- Mersenne Prime
- no
- Sophie Germain Prime
- no
- Safe Prime
- no
- Powerful Number
- no
- Achilles Number
- no
- Prime Index
- 901
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Numbers k such that k^2 and k have same last 3 digits.at n=29A008853
- Ceiling of Gamma(n+1/8)/Gamma(1/8).at n=9A020118
- Numbers k such that the continued fraction for sqrt(k) has period 77.at n=3A020416
- Primes that remain prime through 2 iterations of function f(x) = 8x + 1.at n=20A023260
- Primes that remain prime through 3 iterations of function f(x) = 10x + 9.at n=25A023301
- Primes that are palindromic in base 6.at n=23A029974
- Base-6 palindromes that start with 5.at n=28A043014
- a(n)=(s(n)+3)/10, where s(n)=n-th base 10 palindrome that starts with 7.at n=22A043086
- Primes with first digit 7.at n=18A045713
- Primes p such that pp'-2 is prime, where p' denotes the next prime after p.at n=40A048797
- a(n) = a(n-1) + a(m) for n >= 4, where m = 2^(p+1) + 2 - n and p is the unique integer such that 2^p < n - 1 <= 2^(p+1), starting with a(1) = 1, a(2) = 2, and a(3) = 4.at n=42A050053
- Primes p such that number of primes produced according to rules stipulated in Honaker's A048853 is 4.at n=22A050666
- Least prime in A031930 (lesser of 12-twins) whose distance to the next 12-twin is 2*n.at n=7A052355
- Sum of composite numbers between prime p and nextprime(p) is palindromic.at n=16A054266
- Sum of composite numbers between prime p and nextprime(p) is palindromic with restriction 'p + 1 <> sum'.at n=10A054267
- Prime number spiral (clockwise, Southeast spoke).at n=15A054564
- Primes p such that p^6 reversed is also prime.at n=33A059699
- Primes p such that the greatest prime divisor of p-1 is 7.at n=35A061638
- Primes whose sum of digits is 8.at n=28A062343
- Primes of form 100*k + 1.at n=23A062800