7873
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 25
- Digital Root
- 7
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 7874
- 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
- 7872
- Möbius Function
- -1
- Radical
- 7873
- 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
- 145
- 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
- 994
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- From a Goldbach conjecture: records in A185091.at n=45A002092
- Numbers k such that the continued fraction for sqrt(k) has period 9.at n=42A010339
- Smallest nontrivial extension of n-th palindromic prime which is a prime.at n=16A030680
- Let a (resp. b,c,d) be number of primes in the range {2..p} that end in 1 (resp. 3,7,9); sequence gives p such that a=d and b=c.at n=40A038562
- Denominators of continued fraction convergents to sqrt(7).at n=14A041009
- Numerators of continued fraction convergents to sqrt(863).at n=7A042666
- Primes at which the difference pattern X424Y (X and Y >= 6) occurs in A001223.at n=15A052166
- Primes followed by a [4,2,4] prime difference pattern of A001223.at n=23A052378
- Third term of strong prime 5-tuples: p(m-1)-p(m-2) > p(m)-p(m-1) > p(m+1)-p(m) > p(m+2)-p(m+1).at n=21A054810
- Primes p with the following property: let d_1, d_2, ... be the distinct digits occurring in the decimal expansion of p. Then for each d_i, dropping all the digits d_i from p produces a prime number. Leading 0's are not allowed.at n=37A057876
- Primes with 3 distinct digits that remain prime (no leading zeros allowed) after deleting all occurrences of any one of its distinct digits.at n=27A057879
- Primes p such that x^41 = 2 has no solution mod p.at n=23A059236
- Primes of the form sum 6d/(2 + mu(d)) for some k and all d dividing k.at n=21A069548
- a(n) = 2^n + 6^n + 9^n.at n=4A074543
- Expansion of (1+31*x-2*x^2-2*x^3)/(1-16*x^2+x^4).at n=5A077397
- a(n) = prime(n*(n+1)/2+4).at n=44A078725
- Vertical of triangular spiral in A051682.at n=41A081271
- Primes which are the sum of three positive 4th powers.at n=16A085318
- a(n)=A085956(3n).at n=31A086361
- Positions of the records in A089294. First integer requiring a larger prime in its representation by (signed) sums of squares of distinct primes than all preceding integers.at n=7A089295