7457
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 23
- Digital Root
- 5
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 7458
- 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
- 7456
- Möbius Function
- -1
- Radical
- 7457
- 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
- yes
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 70
- 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
- yes
- Mersenne Prime
- no
- Sophie Germain Prime
- no
- Safe Prime
- no
- Powerful Number
- no
- Achilles Number
- no
- Prime Index
- 944
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Class numbers of quadratic fields.at n=13A001985
- Numbers that are the sum of 10 positive 7th powers.at n=37A003377
- Number of 3rd-order maximal independent sets in cycle graph.at n=41A007387
- Numbers k such that the continued fraction for sqrt(k) has period 47.at n=15A020386
- Numbers whose set of base-15 digits is {2,3}.at n=18A032815
- Number of partitions of 5n such that cn(1,5) = cn(4,5) < cn(0,5) = cn(2,5) = cn(3,5).at n=13A036892
- Reversed binary packing of Fibonacci sequence A000045.at n=6A048722
- a(n) = a(n-1) + n^2 if n prime else a(n-1) - n, starting with a(0) = 0.at n=46A051353
- Primes p such that p^6 reversed is also prime.at n=37A059699
- Primes starting and ending with 7.at n=16A062334
- Trisection of A007294.at n=32A073471
- Define the composite field of a prime q to be f(q) = (t,s) if p, q, r are three consecutive primes and q-p = t and r-q = s. This is a sequence of primes q with field (6,2).at n=38A073651
- Primes which are 1 mod m, where m is the index of the prime in sequence A002313 (Real primes with corresponding complex primes). The index m can be found in A084166 Primes which are -1 mod m can be found in sequence A084163.at n=10A084165
- Primes p having exactly one partition into distinct divisors of p+1.at n=26A085499
- Smallest member of a pair of consecutive twin prime pairs that have two primes between them.at n=22A089634
- Primes p such that 2^j+p^j are primes for j=0,1,2,4.at n=6A094487
- Lower bound b of twin primes pairs such that b's digital reverse is also prime.at n=35A101781
- Lower bound twin primes such that their digital reverse is prime and a lower bound twin prime.at n=10A101783
- Smaller of twin primes of the form 6*p(j)*p(k)-1, 6*p(j)*p(k)+1 where p(i)=i-th prime.at n=40A102168
- Primes of the form 23n+5.at n=41A102734