7971
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 24
- Digital Root
- 6
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 10632
- Proper Divisor Sum (Aliquot Sum)
- 2661
- 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
- 5312
- Möbius Function
- 1
- Radical
- 7971
- 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
- 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
- a(n) = s(1)t(n) + s(2)t(n-1) + ... + s(k)t(n+1-k), where k = [ (n+1)/2 ], s = (F(2), F(3), ...), t = (primes).at n=18A024597
- Least k such that the first k terms of the Kolakoski sequence (A000002) contain n more 2's than 1's.at n=10A025503
- Numbers k such that the continued fraction for sqrt(k) has even period and if the last term of the periodic part is deleted the central term is 89.at n=6A031587
- Decimal concatenation of n-th lucky number and n-th prime number.at n=19A032604
- Multiplicity of highest weight (or singular) vectors associated with character chi_159 of Monster module.at n=39A034547
- Integers whose set of prime factors (taken with multiplicity) uses each digit exactly once (i.e., is pandigital) in some base b > 1. Numbers are expressed in base 10.at n=36A058760
- a(n) is the least k such that (k*prime(n)#)^2 + 1, ((k+1)*prime(n)#)^2 + 1 and ((k+2)*prime(n)#)^2 + 1 are 3 primes, where prime(n)# is the n-th primorial.at n=30A098765
- a(n) = least k such that the remainder when 20^k is divided by k is n.at n=28A128160
- T(n,k) = 5*A046802(n,k) - 4*A007318(n,k), triangle read by rows (0 <= k <= n).at n=30A168290
- T(n,k) = 5*A046802(n,k) - 4*A007318(n,k), triangle read by rows (0 <= k <= n).at n=33A168290
- Convolved with its aerated variant of two zeros between terms = A000041.at n=40A174068
- Number of partitions p of n such that (number of numbers in p of form 3k) < (number of numbers in p of form 3k+1).at n=35A241743
- Numbers k such that (26*10^k - 131)/3 is prime.at n=22A272402
- Numbers such that the sum of their digits is equal to the sum of digits of their aliquot parts.at n=42A274218
- Position of first appearance of each integer in A088568 (number of 1's minus number of 2's in first n terms of A000002).at n=22A288605
- Solution of the complementary equation a(n) = a(n-1) + a(n-2) + b(n) - 1, where a(0) = 1, a(1) = 3, b(0) = 2, b(1) = 4, b(2) = 5, and (a(n)) and (b(n)) are increasing complementary sequences.at n=15A295960
- Triangle read by rows: T(n,k) is the number of achiral colorings of the edges of a regular n-dimensional simplex using exactly k colors. Row n has (n+1)*n/2 columns.at n=22A327090
- Semiprimes A001358(k) = p*q such that p*q+p+q and r*s+r+s are consecutive primes, where A001358(k+1)=r*s.at n=3A330478
- Main diagonal of A332363.at n=16A332364
- Fourier coefficients of the modular form (1/t_{6a}^3) * (1-12*sqrt(-3)/t_{6a})^(3/2) * F_{6a}^18.at n=4A341573