15679
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 28
- Digital Root
- 1
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 15680
- Proper Divisor Sum (Aliquot Sum)
- 1
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 15678
- Möbius Function
- -1
- Radical
- 15679
- 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
- 84
- 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
- 1830
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Primes that remain prime through 3 iterations of function f(x) = 5x + 6.at n=41A023285
- Primes that remain prime through 4 iterations of function f(x) = 5*x + 6.at n=7A023315
- Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 90 ones.at n=10A031858
- Primes whose sum of digits is the perfect number 28.at n=38A048517
- Primes p such that p and p^2 have same digit sum.at n=26A058370
- Primes p such that x^67 = 2 has no solution mod p.at n=28A059330
- Irregular triangle read by row of the prime factors of 3^(3^n) + 2.at n=8A083020
- a(n)=A085956(3n).at n=38A086361
- Prime(p)-4 for primes p such that prime(p) - 4 is prime.at n=38A094069
- Prime numbers which when written in base 7 have a composite digit-sum.at n=22A096790
- Molien series for group of order 4608 acting on joint weight enumerators of a pair of binary doubly-even self-dual codes.at n=47A097870
- Prime Friedman numbers.at n=10A112419
- Prime numbers p such that p^3 - p + 1 and p^3 + p - 1 are both primes.at n=23A137463
- Primes of the form 55x^2+10xy+199y^2.at n=27A140632
- Primes congruent to 28 mod 47.at n=37A142379
- Primes congruent to 44 mod 53.at n=34A142574
- Primes congruent to 44 mod 59.at n=30A142771
- Primes congruent to 2 mod 61.at n=27A142800
- a(n) = 784*n - 1.at n=19A158399
- a(n) = 20*n^2 - 1.at n=27A158491