8251
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 16
- Digital Root
- 7
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 8512
- Proper Divisor Sum (Aliquot Sum)
- 261
- 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
- 8251
- 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
- yes
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 65
- 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
- Smallest odd number expressible in at least n ways as p+2*m^2 where p is 1 or a prime and m >= 0.at n=45A007697
- Smallest odd number expressible in at least n ways as p+2*m^2 where p is 1 or a prime and m >= 0.at n=42A007697
- Smallest odd number expressible in at least n ways as p+2*m^2 where p is 1 or a prime and m >= 0.at n=43A007697
- Smallest odd number expressible in at least n ways as p+2*m^2 where p is 1 or a prime and m >= 0.at n=46A007697
- Smallest odd number expressible in at least n ways as p+2*m^2 where p is 1 or a prime and m >= 0.at n=44A007697
- Consider all ways of writing a number as p+2m^2 where p is 1 or a prime and m >= 0; sequence gives numbers that are expressible in at least 2 more ways than any smaller number.at n=9A016067
- Cycle class sequence c(n) (the number of true cycles of length n in which a certain node is included) for zeolite BEA = Beta Na7[Al7Si57O128] starting with a T4 atom.at n=12A019070
- Numbers k such that the continued fraction for sqrt(k) has period 84.at n=23A020423
- a(n+1) = [ A*a(n)+B ]/p^r, where p^r is the highest power of p diving [ A*a(n)+B ] and p=2, A=2.00013, B=3.0.at n=42A029580
- Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 46 ones.at n=26A031814
- Second pentagonal numbers with even index: a(n) = n*(6*n+1).at n=37A049453
- Smallest integer that can be expressed as p+2m^2 in more ways than any smaller number, where m >= 0 and p = 1 or prime.at n=30A055202
- Numbers k such that k^6 == 1 (mod 7^4).at n=20A056092
- a(n) = 8*n^2 + 88*n + 43.at n=27A086760
- a(n) = (15*n^2 + 5*n + 2)/2.at n=32A093500
- Let a(1)=0. Then a(i+1)=position of first occurrence of a(i) in decimal expansion of log 2.at n=13A098289
- a(1) = 1; for n > 1, a(n) is the least k > a(n-1) such that a(n) + a(n-1) is square and a(n) - a(n-1) is prime.at n=21A108972
- Numbers k such that phi(k) + prime(k) is a triangular number.at n=32A115908
- Numbers k such that the digits of sigma(k) are a permutation of those of k, in base 10.at n=16A115920
- Connell (5,3)-sum sequence (partial sums of the (5,3)-Connell sequence).at n=60A122795