7993
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 28
- Digital Root
- 1
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 7994
- 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
- 7992
- Möbius Function
- -1
- Radical
- 7993
- 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
- 83
- 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
- 1007
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Centered 12-gonal numbers, or centered dodecagonal numbers: numbers of the form 6*k*(k-1) + 1.at n=36A003154
- Numbers k such that the continued fraction for sqrt(k) has period 65.at n=5A020404
- Least m such that if r and s in {1/3, 1/6, 1/9, ..., 1/3n} satisfy r < s, then r < k/m < (k+1)/m < s for some integer k.at n=39A024838
- a(n) = least m such that if r and s in {1/2, 1/4, 1/6, ..., 1/2n} satisfy r < s, then r < k/m < (k+2)/m < s for some integer k.at n=38A024842
- Palindromic primes in base 8.at n=26A029976
- Lower prime of a pair of consecutive primes having a difference of 16.at n=26A031934
- Concatenation of n-th prime number and n-th lucky number.at n=21A032603
- Sums of distinct powers of 6.at n=41A033043
- Number of partitions of n with equal number of parts congruent to each of 3 and 4 (mod 5).at n=40A035561
- Primes of the form 666*n + 1.at n=4A037029
- Positive numbers having the same set of digits in base 2 and base 6.at n=37A037411
- Sums of 3 distinct powers of 6.at n=13A038479
- Largest prime substring in 6^n (0 if none).at n=7A046272
- Prime islands: for n >= 2, a(n) = least prime whose adjacent primes are exactly 2n apart; a(1) = 3 by convention.at n=22A046931
- Bessel function Y_0(n) is a monotonically decreasing positive sequence.at n=19A046961
- Bessel function |Y_0(n)| is a monotonically decreasing positive sequence.at n=32A046963
- Primes whose sum of digits is the perfect number 28.at n=16A048517
- McKay-Thompson series of class 18E for Monster.at n=18A058535
- Primes p such that x^37 = 2 has no solution mod p.at n=27A059223
- Primes with either no internal digits or all internal digits are 9.at n=47A069684