7559
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 26
- Digital Root
- 8
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 5
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 7560
- 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
- 7558
- Möbius Function
- -1
- Radical
- 7559
- 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
- 132
- 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
- yes
- Powerful Number
- no
- Achilles Number
- no
- Prime Index
- 959
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Numbers m such that 3*2^m - 1 is prime.at n=30A002235
- If x and y are terms, so is x*y + 9.at n=38A009350
- Primes that remain prime through 3 iterations of function f(x) = 7x + 6.at n=13A023290
- Numbers whose least quadratic nonresidue (A020649) is 13.at n=20A025025
- Numbers having period-2 6-digitized sequences.at n=24A031357
- 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=30A031583
- Numbers having four 5's in base 6.at n=9A043392
- Primes with multiplicative persistence value 5.at n=17A046505
- Values of A (the short leg) of a Pythagorean triangle with A and C (the hypotenuse) both prime and part of a twin prime.at n=23A051642
- Primes of the form 4*k^2 + 163.at n=36A057604
- Smaller of twin primes whose middle term is a multiple of A002110(4)=210.at n=9A060230
- Primes p that have exactly two primitive roots that are not primitive roots mod p^2.at n=35A060518
- Primes with 13 as smallest positive primitive root.at n=17A061326
- The least number k = a(n) > a(n-1) for which k!/(k+1)^m for increasing m's.at n=40A061769
- Numbers k such that 15^k - 14^k is prime.at n=5A062581
- Primes p such that (p-1)/2 and (p-3)/4 are also prime.at n=17A066179
- Primes with either no internal digits or all internal digits are 5.at n=50A069680
- Least m which can be written as i*j+i+j in n different ways: A072670(m)=n.at n=31A072671
- Primes p such that p+1 is a highly composite number.at n=13A072828
- Safe primes (A005385) (p and (p-1)/2 are primes) such that 12*p+1 is also prime.at n=25A075707