7247
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 20
- Digital Root
- 2
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 4
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 7248
- 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
- 7246
- Möbius Function
- -1
- Radical
- 7247
- 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
- 119
- 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
- yes
- Powerful Number
- no
- Achilles Number
- no
- Prime Index
- 927
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Primes p == 7, 19, 23 (mod 40) such that (p-1)/2 is also prime.at n=45A000353
- Smallest positive number that can be written as sum of distinct Fibonacci numbers in n ways.at n=69A013583
- Cycle class sequence c(n) (the number of true cycles of length n in which a certain node is included) for zeolite HEU = Heulandite Ca4[Al8Si28O72].24H2O starting with a T4 atom.at n=12A019135
- a(n) = number of integer strings s(0),...,s(n) counted by array T in A026374 that have s(n)=1; also a(n) = T(2n-1,n-1).at n=6A026378
- a(n) = T(n,[ n/2 ]), where T is the array in A026374.at n=12A026380
- T(n,[ n/2 ]), where T is the array in A026386.at n=12A026392
- 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 85.at n=2A031583
- Number of ways to partition n elements into pie slices of different sizes other than one.at n=36A032155
- Numbers whose set of base-15 digits is {2,3}.at n=16A032815
- Nearest integer to n^(5/2).at n=35A036488
- Denominators of continued fraction convergents to sqrt(555).at n=10A042063
- Numerators of continued fraction convergents to sqrt(789).at n=5A042520
- Numerators of continued fraction convergents to sqrt(951).at n=5A042840
- Numbers whose base-5 representation contains exactly three 2's and two 4's.at n=28A045291
- Primes with first digit 7.at n=44A045713
- Integers n such that A047988(n)=3.at n=33A047986
- Primes p from A031924 such that A052180(primepi(p)) = 11.at n=18A052232
- Fifth term of strong prime quintets: p(m-3)-p(m-4) > p(m-2)-p(m-3) > p(m-1)-p(m-2) > p(m)-p(m-1).at n=18A054812
- a(n) is smallest safe prime (A005385) such that a(n) + 12*n is the next safe prime, i.e., x = (a(n) - 1)/2 and x + 6*n are closest Sophie Germain primes.at n=22A059327
- Primes starting and ending with 7.at n=12A062334